n = 17 open ★=

186417714000000≤s(17)≤4.67553009…

The best packing known for 17 squares, side 4.67553009…, John Bidwell 1998
4.6604.676
456
4.1235.123
nn+1

Proven

4.660442≤s(17)≤4.675531

  • new result
  • exact

Citation record n-017

lowerGuzhou0806 after Kleddamag et al. 2026, GitHub (confirmed T-093)

upperBidwell 1998, Squares in Squares (confirmed T-065)

Open

  • optimality

Bounds

Best known packing

4.67553009…

4.67553009360455
Found by
John Bidwell 1998
Construction
hand
Tilt angles
0∘, 39.80495897…∘, −36.62378638…∘
Minimal polynomial, degree 18
4775s18−190430s17+3501307s16−39318012s15+300416928s14−1640654808s13+6502333062s12−18310153596s11+32970034584s10−18522084588s9−93528282146s8+350268230564s7−662986732745s6+808819596154s5−660388959899s4+358189195800s3−126167814419s2+26662976550s−2631254953=0
Source
[Kingbird]
Evidence
E-kingbird-upper-register
Verified upper bound

4.67553009…

4.6755300936045509516342148538535054

The reported value, verified here.

Evidence
E-n017-certified-endpoint
Reported lower bound

186417714000000

Proved by
Guzhou0806 2026
Kind
counting
Scope
This field preserves the source report. The complete paired replay of R071 here on 2026-10-05 carries the same value into the verified field; R070 has not been replayed here.
Note
The R071 release of Guzhou0806/n17-square-packing (30 September 2026) states the strict bound s(17)>18641771/4000000 = 4.66044275 for independently rotated unit squares with disjoint interiors and boundary contact allowed. Guzhou0806 / N17 project, on R068's continuation of Kleddamag's public 4.66001 charge (Kleddamag building on Squares Project (Joshua Levy), Mira and Guzhou0806): every point orbit, rule orbit and weight is R068's, and the strict cores are rebuilt over 5,114 orientation intervals at parent side 18452000/18641771, refining the previous day's R070 (46604427/10000000 over 5,107 intervals). The package credits Kleddamag for the 4.66001 framework, proof and JavaScript checker, discloses AI assistance, says its row-level partition records are missing, and states that its publisher checked file identities and saved records only and did not observe its CI.
Source
[Guzhou0806 n17 R071]
Evidence
E-n017-guzhou-r071-report
Verified lower bound

186417714000000

The reported value, verified here.

Evidence
E-n017-guzhou-r071-source-replay
Gap

0.01508734…

Verified upper minus verified lower.

Results in the register

Verification

upper: audited here; lower: replayed here

—

Rigidity

not rigid, numerically checked, numerical multiprecision

Evidence: E-translation-escape-not-rigid

Scope

Square 5 of the retained witness (witness id 6) translates 0.071507 along (-0.707107, 0.707107) with the packing still valid, so the configuration admits a non-trivial feasible motion; 2 of its 17 squares do. Every constraint is exactly affine in the slide parameter, so the arithmetic carries no linearization error, but the coordinates are the witness's own finite-precision transcription: this settles the retained configuration, not the true optimum. Rigidity and optimality are independent, and this bears only on the former.

Open questions
  • Blocker (mathematics): The certified endpoint is feasible and its side is the root of the catalogue's degree-18 polynomial (exp-245, 2 October 2026); global optimality is not established. E-n017-certified-endpoint, E-n017-catalogue-polynomial-identity
  • Blocker (source evidence): MacIver's historical n17 claim needs the fourteen C1-C14 certificates, exact ledger and theorem-assembly scripts, and their complete replay; those artifacts are absent from the inspected public source commit. E-n017-maciver-reported-lower
  • Blocker (source evidence): The complete source checker has not been independently replayed here. E-n017-anabologyco-weighted-certificate
  • Priority: The manuscript dated 8 August 2026, '[MacIver 2026 n17]', reports s(17) > (40sqrt(2)+19)/17 + 1/200, approximately 4.450208382054341, through conditional counting on a deformed Green scaffold. This historical source claim is weaker than the independently verified 459/100 and has not been replayed here. (David R. MacIver)
Evidence and sources
35 evidence entries

E-kingbird-upper-register, E-nagamochi-lower, E-basic-grid-upper, E-n017-kleddamag-rational-upper, E-n017-certified-endpoint, E-n017-catalogue-polynomial-identity, E-green17-sixteen-point-lower, E-green17-interval-audit, E-n017-massaccesi-source-replay, E-n017-burns-source-replay, E-n017-burns-control-decision, E-n017-mira-point-certificate-replay, E-n017-fort-point-certificate-replay, E-n017-anabologyco-weighted-certificate, E-n017-massaccesi-h052-agreement, E-n017-maciver-reported-lower, E-n017-kleddamag-461300-99853-report, E-n017-kleddamag-461300-99853-source-replay, E-n017-kleddamag-466001-report, E-n017-kleddamag-466001-source-replay, E-n017-kleddamag-4640020-report, E-n017-kleddamag-4640020-source-replay, E-n017-guzhou-r071-report, E-n017-guzhou-r071-source-replay, E-n017-guzhou-r068-report, E-n017-guzhou-r068-source-replay, E-n017-guzhou-r067-source-replay, E-n017-guzhou-r052-report, E-n017-guzhou-r052-source-replay, E-n017-guzhou-r012-source-replay, E-n017-guzhou-r012-interval-decision, E-n017-mira-4613-exact-replay, E-n017-mira-4613-interval-decision, E-n017-fractional-certificate, E-fractional-interval-decision

s(17) — open

s(17)≤4.6755300936045509516342148538535054 is now certified by exact identities and rational interval bounds. The reported record, 4.67553009360455…, was found by John Bidwell in 1998, building on a packing of Hämäläinen’s from 1980. The certified packing’s side is exactly that record: it is the root of the catalogue’s degree-18 polynomial, which is irreducible over ℚ (exp-245; until 2 October 2026 this page recorded that identity as unproved), and the decimal above is a rational outward ceiling on it. The verified lower bound is the strict inequality s(17)>18641771/4000000=4.66044275, from Guzhou0806 / N17 project’s R071 release, published on 30 September 2026 and replayed here on 5 October, 11/4000000 above R068’s 116511/25000, whose charge it keeps. R071 keeps every point orbit, rule orbit and weight of R068 and rebuilds every strict core over 5,114 orientation intervals, with parents of side 18452000/18641771 in the same container 4613/1000. The budget stays 17000448944 units of 10−9, and the counting surplus stays 17×1000026844−17000448944=7404. The package credits Kleddamag for the 4.66001 framework, proof and BigInt checker, and discloses AI assistance; its publisher checked file identities and saved records only, its row-level records are missing, and its CI replay passed unobserved, so the replay here is its first independent check. Both of its checkers ran here over every interval, Guzhou0806’s own C++ checker and Kleddamag’s Node BigInt checker, the bytes R068’s replay here ran, and agree with each other on every interval minimum and cell count, every row at 1000026844; both refuse two mutated certificates. This supports V3/C3 on one machine method: the two sweeps are one event-cell method, and this repository’s native parent-core route models only k-of-m threshold atoms, so it cannot yet read the weighted and winning-subset features and gives no method-distinct decision. The proof review found no mathematical defect, re-derived every premise the new parent side and cores touch, and reproduced 227 rows of the replay’s ledger with a sweep sharing no code with the source; the two steps the source’s proof asserts are proved in the review of R067 and R068, and neither uses the parent side. R070’s obstruction shows this charge cannot prove a bound 1/40000000 higher, so a further step needs a new charge. The gap to the catalogue’s printed record is 0.01508734360455.

The previous verified lower bound was 116511/25000=4.66044, from Guzhou0806 / N17 project’s R068 release, published on 28 September 2026 and replayed here that night, 43/100000 above Kleddamag’s 4.66001, whose charge it continues. R068 keeps that charge’s 889 rule orbits and their weights unchanged, moves one zero-weight site orbit by 1/12500, adds one weighted four-site point orbit on the diagonal at (1.34,1.34), and rebuilds the strict cores over 4,991 orientation intervals, with parents of side 115325/116511. Its two checkers, the same as R071’s, ran here over every interval and agree with each other and with the published ledgers. The same day’s R067, 233009/50000=4.66018, ran the 4.66001 charge unchanged at parent side 32950/33287 over 2,808 intervals; it was replayed here in full too and never held the verified field. R070 of 29 September, 46604427/10000000=4.6604427 over 5,107 intervals, is the release R071 refines; it was never replayed here and never held the verified field.

Before R068 the verified lower bound was 466001/100000=4.66001, published on 27 September 2026 and replayed here the same day. Kleddamag, building on Squares Project (Joshua Levy), Mira and Guzhou0806: an exact weighted-certificate proof over 2,168 orientation intervals. That is the lineage the release’s own ATTRIBUTION.md states — this project’s weighted-covering, strict-core, event-cell and threshold-budget methods, Mira’s 17squares support and parent-angle catalogue, and R038’s parent-side reduction — and the release claims no invention of those methods and says that attribution implies no upstream coauthorship or endorsement. Its AUTHORS.md says the work was produced with AI agents (OpenAI Codex) under Kleddamag’s direction. It keeps Kleddamag’s parent-core architecture — container side 4613/1000, here with parents of side 461300/466001 — and combines two completed charge candidates: 224 point orbits, 225 two-of-three, 30 three-of-five and two four-of-seven threshold orbits, 154 weighted-threshold orbits in four coefficient patterns and 254 pairwise-intersecting winning-subset orbits on three to ten sites, 7,048 feature images in all over 2,620 site orbits (20,856 sites). Every one of its 86 distinct rules has capacity one. Both of the source’s complete checkers, a Python sweep in rational arithmetic and a JavaScript BigInt sweep, are the v1.1.0 engines byte for byte; they ran here over every interval and agree on every interval minimum and cell count. The counting surplus is 17×1000026844−17000402008=54340 units of 10−9. This supports V3/C3 on one machine method: the two sweeps are one event-cell method, and this repository’s native parent-core route models only k-of-m threshold atoms, so it cannot yet read the weighted and winning-subset features and gives no method-distinct decision. The proof review is a separate record, docs/project/reviews/review-2026-09-27-n17-kleddamag-466001.md. R068 exceeds it by exactly 43/100000=0.00043.

Before that the verified lower bound was 232001/50000=4.64002, from Kleddamag’s v1.1.0 release of 26 September 2026, replayed here on 27 September: Kleddamag, building on Squares Project (Joshua Levy), Mira and Guzhou0806, on the same lineage. It widened Kleddamag’s own v1.0.0 charge dictionary to 280 point orbits, 155 two-of-three, 26 three-of-five and one four-of-seven threshold orbit, 54 weighted-threshold orbits (coefficients 2,1,1,1, threshold 3) and 30 pairwise-intersecting winning-subset orbits over 2,048 angle intervals, with parents of side 32950/33143 and a counting surplus of 17×998727933−16978369232=5629 units of 10−9, also at V3/C3. Its review found no mathematical defect. Its AUTHORS.md says Kleddamag directed the work and that separate OpenAI Codex research tasks constructed and exactly checked the 4.640020 certificate. The 4.66001 bound exceeds it by exactly 1999/100000=0.01999.

Before v1.1.0 the verified bound was 231001/50000=4.62002, from the R052 release of Guzhou0806 / N17 project, published on 25 September 2026 and replayed and reviewed here the same day. R052 was produced with AI assistance on Kleddamag’s v1.0.0 mixed point/threshold parent-core architecture and extends Guzhou0806’s own R050 with enlarged resources: 2,354 point orbits and 514 two-of-three and 54 three-of-five threshold orbits (18,585 sites, 4,504 groups, 2,922 columns) over 15,721 angle intervals. Its SOURCE_NOTICES.md says Guzhou0806 / N17 project used AI assistance for exploration, implementation, computation, checking and documentation, with non-proposer AI review in its final local acceptance, and names Mira-acc/17squares and Joshua Levy’s squares project in its method lineage. The source’s Python/Numba and Node/BigInt sweeps both ran here over every interval, and each reproduced the source’s own row ledger byte for byte. The counting surplus is 17×999426274093−16990246659579=2 units of 10−12, no slack beyond integer rounding. That too is V3/C3 on one machine method: the native interval route verifies every exact premise but refuses the coverage at its engine ceilings. Its review found no mathematical defect. Kleddamag’s v1.1.0 exceeds it by exactly 1/50=0.02.

Before R052 the verified bound was 461300/99853=4.619791092907…, from Kleddamag’s v1.0.0 release, replayed and reviewed here on 21 September 2026. Its complete Python and JavaScript scans cover all 7,853 parent-angle intervals, agree on all 509 histogram bins, and give 17×1000020517−16998427356=1921433 integer units of counting surplus, also at V3/C3. R052 exceeds it by 1142853/4992650000≈0.000229. Its AUTHORS.md says Kleddamag initiated and directed the project and OpenAI Codex performed the mathematical exploration, the searches and checks, and the certificate and proof. Before that, the verified bound was 461300/99999=4.61304613…, from Guzhou0806’s R012 parent-angle certificate of 20 September 2026 (T-032), which remains valid historical evidence at V3/C3, confirmed by two machine methods: the source’s own checker re-run, and an independent re-implementation here.

R012 uses this repository’s weighted method with three changes and was the first external certificate to supply this case’s verified bound. Instead of covering every closed B-square, it covers only what a real parent needs: squares of side A=99999/100000 inside [0,4613/1000]2, with the bound L/A recovered by rescaling at the end. A catalogue of 2925 closed parent-angle intervals covers [0,π/4], and each interval chooses its own concentric closed core — its own direction and its own side — strictly inside every parent of that interval. Coverage is then required only over the legal parent-centre square for the interval, which is smaller than the set of all contained cores, and that restriction is what the extra strength buys: five placements the source retains as counterexamples fail the unrestricted test and pass this one. The measure is 1616 atoms in 206 D4 orbits of total mass 424969/25000, every core captures at least γ=250023/250000, and 17γ exceeds the mass by 701/250000. It is decided at V3/C3 by two methods that fail differently: the source’s own exact event-cell checker, which recomputed all 2925 intervals here over 9,231,165 centre strips, and this repository’s interval branch and bound, which certified the same 2925 entries over 34,465,227 boxes with none stalled and every bracket containing the exact minimum. The catalogue minimum is exactly γ, so there is no slack anywhere: raising the threshold by one part in 106 at an entry that attains it is refused.

Beneath it sits the certificate R012 is built on, which was the strongest value on record until R012 passed it thirteen days later. Mira’s weighted certificate of 7 September 2026 gives s(17)≥4613/1000=4.613 on 1620 atoms of mass 849899249/50000000, core side 19997/20000 and a 2880-step direction net, with least covered mass 1000002103/1000000000. It is written in this repository’s own certificate schema — it starts from the T-019 atoms and retains that file unchanged — so both stock verifiers decide it with no translation layer, and both accept it: the exact sweep finds that least value at net direction 2194, and the interval route pins it on the doubled 5761-direction net to a zero-width enclosure at the same rational. Mira’s own headline is larger, the dilation endpoint 4.61302863588611…, but that step needs a T-022-style proof note this certificate does not carry, so the record holds the container side. Nothing is lost: R012’s value is larger still.

Both results descend from this repository’s T-019 and credit it, and both disclose model assistance and claim neither peer review nor priority. R012’s ATTRIBUTION.md names it as research by “Guzhou0806 / N17 project, with AI assistance”, and Mira’s paper says its earlier computation and exposition “were developed with assistance from OpenAI’s GPT-5.6 Pro under human direction” and that the September patch and its integration also used AI assistance. Mira’s certificate was published hours after the 7 September GitHub check that built the earlier packet, which is why neither was in the record until 20 September. The two are separate results with separate premises: R012 recomputes every obligation on its own measure and does not depend on Mira’s certificate being valid. What the machines do not decide is the reduction from a packing to R012’s 2925 finite obligations — the angle folding, the endpoint containment test, the union of centre squares, the counting and the rescaling. Those were read line by line in the proof review, which found no error and supplied two steps the source’s note omits.

Weaker bounds are kept for their provenance rather than their strength. This repository’s own T-019, s(17)≥459/100=4.59 of 2026-09-04, held the case until R012 displaced it: 1184 rationally weighted atoms of total mass 423327/25000, least covered mass 200009/200000, decided by the same two verifiers. It is still the ancestor of everything above it, and it still holds n=18 and n=19 in company with the certificates that have since passed it there. Gustavo Massaccesi’s August 2026 certificate ([Burns–Massaccesi n17], T-015) gave 22529/5000=4.5058 — 168 rationally weighted atoms of total mass 203/12<17, reduced exactly to 181 rational directions and 16,562,293 event cells — and held this case from 2026-09-03 until T-019 displaced it a day later. It is source-backed, from a blog post by Massaccesi, who marks the value “(?)”; it is replayed here twice, by the retained source verifier and by an accumulation-independent repository instrument that agrees on every direction cell (H-052, exp-059), with the argument audited lemma by lemma (BC-150 packet, BC-151 review). It is also the control that tests this repository’s verifiers rather than its certificates, and it still is. Massaccesi’s certificate re-parametrises Sam Burns’s note of 6 August 2026, which proposed the side 44811/10000=4.4811 on 268 atoms of total mass 16.9476 with least covered mass 10003/10000, and whose verifier is the one Massaccesi modified; that verifier replays here unchanged (E-n017-burns-source-replay, 7 September 2026), the repository’s exact sweep accepts the same atoms re-encoded as a control (E-n017-burns-control-decision, a published control whose least covered mass is not exactly 1), and its rung sat between Brandwijk’s 89/20 capsule of 18 July and Massaccesi’s value for a fortnight. The note’s byline is “ChatGPT (GPT-5.6 Pro, OpenAI)”; Burns’s post says the model “developed the certificate during this project” and that he operated it. Burns’s companion post describes a near-record arrangement at side 4.677648, 0.002118 above Bidwell’s, with eleven axis-aligned squares and six at a common tilt of 39.6319∘, a contact topology he reports as distinct from Bidwell’s; the coordinates are retained under resources/web/burns-n17-series-addendum-2026-09-07/, and the contact graph has not been reconstructed here. Below it, the repository’s own sixteen-point certificate — cases/green17, s(17)≥4.426213, T-001, certified by the Bentz-lemma cell certificate and an independent interval branch-and-bound — was previously the second strongest and remains a first-party theorem confirmed by two methods, its producer’s code re-run and an independently re-implemented interval audit, above Nagamochi’s general 4.162278 and a hair below Green’s reported but sourceless (402+19)/17≈4.4452. Certifying the sixteen-point set at its exact ceiling 753/250+2≈4.42621356 is a typed follow-on (think-iye2). Green’s own sixteen points, which DS7’s Figure 34 calls unavoidable at his value, are not: a closed unit square in the container misses all of them by 0.00545, so the figure proves no bound above about 4.3978 (review). An earlier audit catalogued eight public lower-bound postings for this size between 18 July and 21 August 2026, and the record’s indexed corpus held three of them. Kim Brandwijk’s Zenodo capsule of 18 July gave 89/20=4.45 from an exact sixteen-point set; Burns’s note of 6 August gave 44811/10000=4.4811. Three GitHub repositories followed, none of them in the indexed corpus until the 7 September 2026 check that found them ([GitHub n17 certificates 2026]): Mira’s first version on 10 August at 4.450837, Stanislav Fort’s on 11 August at 4.456575, and Mira’s second on 11 August at 4.468292. Those three are exact sixteen-point certificates on one architecture — the pose space subdivided in integer arithmetic into point, piercing and infeasible leaves — and they are the strongest integral sixteen-point bounds on record, above both Brandwijk’s capsule and cases/green17; Mira’s and Fort’s replay here under their own Python checkers (E-n017-mira-point-certificate-replay, E-n017-fort-point-certificate-replay). anabologyco-maker’s repository followed with 4.57 on 13 August and the side 9141/2000=4.5705 on 16 August: 560 weighted atoms on the 1/4000 grid, decided not over a direction net but over an exact orientation partition of 148,937 cells, with a Lean 4 layer over the finite checks. It is source-backed only — its decisive Sturm, endpoint and coverage stages need Boost and its Lean layer needs Lean 4.33, neither available here (E-n017-anabologyco-weighted-certificate) — and it was the strongest public value on record until Mira’s certificate of 7 September passed it. Massaccesi’s 22529/5000 closed the sequence on 21 August. Corrected 2 October 2026: Nagamochi’s value is now a reported bound, his Lemma 1 being false (Karakuş 2026; review). This register had recorded that proof as verified, its own error, logged as defect D-516.

Later public claims improved on the historical R012 value 461300/99999.

Guzhou0806’s R038 certificate, in the same repository, reports the strict lower bound 461300000000/99974999999=4.614153538431…. Its complete published proof, checker, source pin and source-result files are now retained in the Guzhou source tree. That release keeps its required Mira numerical certificate external, identified by SOURCE_PIN.json; retaining the tree does not replay the geometric obligations. No local complete R038 replay is claimed, and the verified field does not rely on it.

Kleddamag’s 461300/99853=4.619791092907…, the v1.0.0 release, was the verified bound from 22 to 25 September 2026 and is now the previous one. Its bytes are retained here, a full two-checker replay reproduced its published RESULT.json byte for byte, and the review found no blocking defect. The verified field recorded that result through E-n017-kleddamag-461300-99853-source-replay, which remains valid evidence. The decision before 22 September to wait for a method-distinct checker was an admission-policy error: the complete rigorous replay and discharged proof assumptions already supported a verified bound at C3. The replay date remains 21 September; no new full replay was run for that record correction on 22 September.

The packet retains the source’s manifest-bound result bytes, and Session 150 and the review attest that the local run reproduced them. A separately named local raw replay directory was not retained; the source outputs are not relabelled as local receipts. T-032 keeps its original R012 statement and evidence; adopting the stronger external bound neither rewrites that result nor creates a new theorem identifier.

Guzhou0806 then published three releases on Kleddamag’s architecture, each numerically superseded by R052 and each retained here only as a publication record in the R052 packet, none replayed: R042 on 23 September (115325/24963≈4.619837), R043 the same day (461300/99851≈4.619884), and R050 on 24 September (4613000/998509≈4.619888). R052’s geometry is R050’s, uniformly rescaled, with five of R050’s 15,706 angle rows each split into four. The complete R052 package, its four replay receipts and the native route’s refusal are retained here, and the verified field records the result through E-n017-guzhou-r052-source-replay. As with Kleddamag’s bound, no new theorem identifier is created. Deciding the certificate natively needs the interval engine’s atom, site and member-slot ceilings raised in a new proof commit; a sizing run on four of its rows prices the full run at roughly 8 to 49 CPU-hours, an estimate and not a decision.

Kleddamag’s v1.1.0 release of 26 September 2026 then raised the bound to 232001/50000=4.640020. Its new package, bounds/4.640020/, carries the certificate, a proof and method note, a general-rule Python checker and a separately written JavaScript BigInt checker, a controls script, and the source’s own receipts; the v1.0.0 files are unchanged in the same tree. The release measures its advance against its own 4.619791…, not against R052, and states that no code from R052 was used. The packet retains every file that changed or was added since v1.0.0, and the verified field records the result through E-n017-kleddamag-4640020-source-replay. As with the earlier external bounds, no new theorem identifier is created. Its budget rules go beyond the architecture reviewed on 21 and 25 September: a weighted threshold charges at most ⌊Σai/k⌋ disjoint cores, and a winning-subset feature whose listed subsets pairwise intersect charges at most one. Deciding it natively needs the parent-core route to represent both feature kinds before any coverage engine question arises.

A later revision of the same repository, of 27 September 2026 and not yet tagged (its changelog lists it as unreleased), then raised the bound to 466001/100000=4.66001 in a new package, bounds/4.66001/. Its checkers and their shared modules are the 4.640020 bytes; only the launcher’s target and interval count and the controls’ target and sampled intervals change. The certificate combines completed charges from two separate research tasks and subdivides eight of an original 2,048 intervals sixteen ways with regenerated strict cores, keeping the charge fixed. Its embedded source string still reads “exact diagnostic pending”, which the release explains as preserved text from an earlier construction stage, kept so that the certificate file is unchanged. The packet retains every file that changed or was added since v1.1.0, and the verified field records the result through E-n017-kleddamag-466001-source-replay. No new theorem identifier is created. The feature kinds and budget rules are the ones v1.1.0 introduced, on many more orbits: the weighted thresholds now include coefficients 2,1,1,1,1,1 at 4, 2,1,1,1,1,1,1,1 at 5 and 4,1,1,1,1,1 at 5, each still firing at most once on disjoint cores, and the winning-subset rules run on three to ten sites.

Guzhou0806 / N17 project’s R067 and R068 packages, published on 28 September, are retained with complete paired replays of both in their packet. The verified field recorded R068 through E-n017-guzhou-r068-source-replay from 29 September to 5 October, and R067, the intermediate, is recorded through E-n017-guzhou-r067-source-replay. As with the earlier external bounds, no new theorem identifier is created. R068 also ships the C010 research material: a shifted-core strip sweep and an exact counterexample to a separate charge aimed at 9321/2000, which the source says is not a global bound and which carries none here.

Guzhou0806 / N17 project’s R070 and R071, published on 29 and 30 September, are retained in their packet, with the complete paired replay of R071 here and its two mutated-certificate controls. The verified field records R071 through E-n017-guzhou-r071-source-replay; R070 has no entry and was not replayed. Both keep R068’s charge exactly — every point orbit, rule orbit and weight, the budget 17000448944 and the requested minimum — and rebuild every strict core for a smaller parent. R070 claims 46604427/10000000=4.6604427 over 5,107 intervals that refine R068’s 4,991, and publishes complete four-partition C++ and BigInt ledgers, which agree row by row here: every interval at minimum 1000026844, surplus 7404. R071 is built on R070’s certificate, bisects seven of its intervals, and claims 18641771/4000000=4.66044275 over 5,114; its row-level records are missing, as the source says, and a completion summary of a three-partition run reports the same minimum and surplus and names the BigInt checker and launcher bytes R068’s replay here ran. The replay here regenerated both ledgers: the two agree on every row, every row at minimum 1000026844, 2,263,809,819,494 cells in all. The source’s own GitHub Actions replays of both passed; their publisher, which discloses AI assistance, did not observe them. Neither release’s other material carries a bound: R070’s same-budget overlay of 319 orbits and its obstruction at one parent within a fixed-weight enhancement class, and R071’s conditional joint geometry at 9321/2000 inside one first-anchor box, which the source says does not prove s(17)>4.6605.

Three other public reports are recorded without carrying a bound here. ahyangyi’s 17squares v1.1.1 of 23 September reports 184547267428061/40000000000000≈4.6136817, below R038 and below the verified bound; its author’s commit message says it is not frontier any more, and it is not retained. Kleddamag’s untagged v1.2.0 of 29 September reports 46601/10000=4.6601, its 4.66001 charge unchanged over 2,543 intervals, with a research checkpoint of conditional exclusions and unfinished routes that claims no bound; it is below R067 and below the verified bound, asks for no work, and is not retained. R052’s source also reports that Kleddamag holds an unpublished internal strict bound of 4.62001. That is second-hand, below R052 and unverified, and it is not recorded here as a bound.

Guzhou0806’s R052 continuation, published on 25 September, claims s(17)>462003/100000=4.62003 from R052’s sites moved by an exact D4-symmetric deformation and two more angle rows split four ways (15,727 rows, surplus again 2 units). Kleddamag’s public 232001/50000=4.64002 of 26 September supersedes it, so it is kept only as a publication record in its own packet, with local receipts for its records, containment and new C++ full replay. That C++ kernel runs the same exact event-cell sweep as the source’s Python and Node/BigInt checkers, so it is not a method-distinct decision.

An additional source, David R. MacIver’s manuscript dated 8 August 2026, reports s(17)>(402+19)/17+1/200≈4.450208382054341 by deforming Green’s sixteen-point scaffold and using conditional counting. The archived source review retains the paper at its public 10 August commit, together with his center-area and center-count manuscripts. The n17 claim is historical and source-reported: the public Lean file proves supporting algebra, while the fourteen certificate files and exact ledger/assembly scripts needed for the full bound are absent from the inspected snapshot. The operative verified lower bound is Guzhou0806’s strict R071 bound 18641771/4000000 described above; the MacIver claim remains historical and source-reported.

Certified Endpoint Upper Bound

The exact root and centroid construction certify 17 unit squares in a square of side at most 4.6755300936045509516342148538535054. This is a rational outward ceiling, not a claim that the endpoint side equals that decimal. The endpoint review records all 68 wall and 136 pair obligations and an independent exact interval audit. It improves the earlier rational witness at 4675530093604551/1015, which remains a verified fallback.

The upper ceiling agrees with Bidwell’s catalogue decimal at its printed precision, and since 2 October 2026 the side is identified exactly. The chart polynomials’ resultant has one irreducible degree-18 factor with a root at the certified point, and mapped to the side it is the catalogue’s polynomial with unit 1 (H-265, exp-245, output review). The certified side is therefore Bidwell’s algebraic number S*, and the decimal is a ceiling on it. Neither result proves a global minimum. The lower bound remains strictly below it, so status remains open.

The attempt to prove s(17)=S* follows the local half, global half and capture that settled n=11. Each part and the evidential status of each claim are explained in The n = 17 Optimality Proof, Explained. None of it moves a bound or the status.

Three orientation classes, and a correction

This is the smallest case whose best known packing uses squares at three different angles, a distinction frequently misattributed to n=11 (which uses two: axis-aligned and ≈40.182∘). Bidwell’s packing uses the unequal nonzero orientations +39.8049589798∘ and −36.6237863834∘, not the symmetric shorthand ±40∘ previously stored here. Those values are transcribed from the analytic entities in the primary Kingbird SVG. The certified endpoint is a separate exact reconstruction. Its side is the catalogue’s degree-18 root (exp-245); that its configuration is the pictured packing, contact for contact, has not been established.

Degree 18

The catalogue reports a side length algebraic of degree 18 — more than twice the degree at n=11, and a useful calibration on how fast algebraic complexity grows once the contact graph stops being simple. Gensane and Ryckelynck derived it from a four-equation system of degree 7 in cosθ1,cosθ2,sinθ1,sinθ2, and observed that Friedman’s rounded 4.6755 “seems to be false.”

Their reported decimal and the catalogue’s differ from the ninth decimal onward (4.6755300960455 versus 4.67553009360455). Direct evaluation resolves the numerical discrepancy in favour of the catalogue: the stored degree-18 polynomial has a root 4.6755300936045509516…, within 9.52×10−16 of the catalogue decimal, while the reported decimal is 2.44×10−9 away and gives polynomial residual about 56.9. The remaining source question is whether the paper has a decimal transcription slip or intended a different equation. Since 2 October 2026 the certified endpoint’s side is identified with that root exactly (exp-245). The polynomial is irreducible over ℚ, by factorization and by Rabin tests at four primes in the independent review. S* therefore has algebraic degree 18, with this polynomial as its minimal polynomial; the review encloses S*=4.6755300936045509516341112704831466487671… to width 10−40.

Why it matters downstream

s(17) is a workhorse: the catalogue records several larger records — s(83), s(84), and others — as extensions of Bidwell’s packing. An error in it would propagate.

Reported Lower Bound

The reported lower bound is Guzhou0806’s strict R071 bound s(17)>18641771/4000000=4.66044275, on R068’s continuation of Kleddamag’s 4.66001 charge (retained packet), and since its complete paired replay here on 5 October 2026 it is the verified bound too, described above. R068’s 116511/25000, R070’s 46604427/10000000, Kleddamag’s 466001/100000, its v1.1.0 232001/50000, Guzhou0806’s R052 231001/50000, Kleddamag’s 461300/99853, Guzhou0806’s earlier R012 result and R067 remain recorded above as historical evidence.

Verification Code

The programs behind this case’s verified bounds, by their evidence. The code column says how the code that ran stands to the code its producer used. VERIFIERS.md says what each program is and whose it is.

bound evidence run code programs
verified lower E-n017-guzhou-r071-source-replay replayed here producer’s code V-guzhou-n17-verify-cpp, V-kleddamag-n17-verify (external); V-audit-guzhou-r071, V-replay-guzhou-r071 (first-party, premises)
verified upper E-n017-certified-endpoint audited here independent V-n17-endpoint-checkers (first-party); V-audit-n17-endpoint-receipt (first-party, premises)