T-080: Linear-measure lower bound replayed at n=101…105

V3 C3 lower bound confirmed

2026-10-02 published · wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · 5 cases, n=101 to 105

A measure of points, segments and rectangles that wand125/square-packing-bounds published on 2 October 2026 proves s(101)≥257/25 = 10.28. Its mass is below 102 to 105, and a packing of any of those counts contains one of 101, so it also gives s(102),s(103),s(104),s(105)≥257/25: five counts in all.

The measure is 333 point, 897 segment and 4 rectangle orbits under D4, with exact rational geometry, of total mass 10099999/100000, at core side 9977/10000 on 201 net half-angles of step 83/40000. It is accepted at all 201 net angles, the axis included, by code/unified_linear_verify.cpp: an outward-rounded interval branch and bound over centre boxes in one quadrant of the centre domain, which the measure's quarter-turn symmetry makes stand for the whole, counting points in the closed core, segments by the length inside and rectangles by the area inside.

The value exceeds Green's reported 10.2467362... at n=101 to 104, by more than 0.0332, and Nagamochi's 1 + sqrt(86) = 10.2736... at n=105. It passed a complete replay here on 2 October 2026 of the source's unchanged checker and replay functions on its pinned tarball: all 201 directions, each returning the certificate's own record. The replay runs the source's own algorithm and is not an independent decision of coverage.

wand125 after Tokoharu and Levy, square-packing-bounds. Registration was requested in jlevy/squares#294. The source says parts of the work were produced with AI assistance under human direction.

Significance, composition and next rung
Significance
Raised the verified lower bound at five counts, n=101 to 105, from Nagamochi's closed form past Green's reported values, by a certificate kind new to this record that adds points and segments to the rectangle densities. Further sizes from one generator at S3, as T-073; the 2 October review of the certificates confirmed S3. Nagamochi's closed form has been a reported bound since Karakuş's finding (T-085, merged 2026-10-03); the verified floor it left at these counts, Karakuş's general bound (T-083), is lower still.
Composition
One primary certificate, on its reported entry and its replay entry. n=102 to 105 take it directly, its mass being below them, so no step is added. The replay runs the source's C++ checker unchanged: one interval-certified method, replayed here, C3. Coverage is decided by that checker alone.
Next rung
V4 and C4 need two adversarial AI reviews by distinct reviewers and a human oversight record; one adversarial review is retained, read before the replay. A second machine method would be a method-distinct decision of rotated coverage for a linear measure; the replay here runs the source's own checker.
Novelty
previously-published Present in an identified source

The cases

This result concerns 5 cases, too many to draw one by one. Each is listed with the film’s bounds, the proved lower bound and the best known side, and links to its case record, where its packing and number line are drawn.

nProved lowerBest knownGapStatusRecords
10110.28000010.5355340.25553390…open=frontier n-101.md
10210.6058290.32582869…frontier n-102.md
10310.6792330.39923204…frontier n-103.md
10410.7071070.42710678…frontier n-104.md
10510.7906770.51067657…frontier n-105.md

Results on these cases

16 results in the register on these cases, oldest first
  1. 2005 published T-007 · 5 of these cases

    s(n)≥min(⌈n⌉,n−2⌊n⌋+1+1) for 4≤n≤324

    lower bound incomplete on these cases, superseded by T-073 and T-080

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085 · 5 of these cases

    Nagamochi 2005, Lemma 1 is false for every container with a>3 and b>2

    correction confirmed

    Karakuş; chelokot · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register

  3. 2026-09-27 published T-056 · cases 102, 103, 105

    Smaller packings for 49 counts from n=68 to 307, each certified two independent ways

    upper bound confirmed superseded by T-125

    Couzo · franciscouzo square-packing 2026-09-27 · packet · register

  4. 2026-09-29 published T-083 · 5 of these cases

    s(n)≥1/2+n−⌊n⌋+1/4 for every nonsquare 8≤n≤324

    lower bound confirmed on these cases, superseded by T-073 and T-080

    Karakuş · Karakuş 2026 · source · register

  5. 2026-10-02 published T-073 · 5 of these cases

    Linear-measure lower bounds replayed at n=83 and n=101…105

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear certificates 2026-10-02 · packet · source · review · register

  6. 2026-10-02 published T-080 this result · 5 of these cases

    Linear-measure lower bound replayed at n=101…105

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear certificates 2026-10-02 · packet · source · review · register

  7. 2026-10-05 published T-098 · cases 102, 103

    Exact optima of 48 known-best packings: s(n) ≤ S', 3.5e-13 to 5.0e-11 below each printed side

    upper bound confirmed on these cases, superseded by T-125

    Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register

  8. 2026-10-05 published T-101 · cases 101, 104

    Exact certificates of 77 catalogue packings: s(n) ≤ S', 1.2e-16 to 9.8e-15 above each side

    upper bound confirmed

    Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register

  9. 2026-10-07 published T-117 · case 105

    Exact rational ceiling refinements at n=105, 292

    upper bound confirmed on these cases, superseded by T-125

    Rehwaldt after Couzo and earlier contributors · Rehwaldt Couzo refinements 2026-10-07 · packet · register

  10. 2026-10-07 published T-120 · case 102

    Reported s(102) ≤ alpha_102 with a degree-8 exact side form

    upper bound recorded superseded by T-125

    Daniel after Couzo · Daniel exact and local reports 2026 · packet · register

  11. 2026-10-07 published T-129 · case 105

    Three dated Daniel certificate reports with historical source custody

    upper bound recorded superseded by T-125

    Daniel after Couzo, Levy · Daniel dated certificates 105 and 130 2026-10-07 · Daniel dated certificate 292 2026-10-07 · packet · packet · packet · register

  12. 2026-10-08 published T-125 · cases 102, 103, 105

    Complete rational construction reports at 25 counts

    upper bound confirmed

    ry-xu · ry-xu square packing 2026 · packet · register

  13. 2026-10-08 published T-128 · case 105

    Eight complete rational refinements from Francisco Couzo

    upper bound confirmed

    Couzo after Xu, Chaoweeraprasit, Gupta, Ellsworth, Daniel, Levy · Couzo exact refinements 2026-10-08 · packet · register

  14. 2026-10-08 published T-130 · case 105

    Five follow-up rational refinements from Francisco Couzo

    upper bound confirmed

    Couzo after Xu, Daniel, Ellsworth, Levy · Couzo follow-up refinements 2026-10-08 · packet · register

  15. 2026-10-09 published T-138 · cases 103, 105

    Exact witnesses at Mishapolk's printed ceilings, the smallest known at 103 and 258 when registered

    upper bound confirmed

    Mishapolk after Stenlund, Friedman, Ellsworth, Chaoweeraprasit, Couzo, Xu, Levy · Mishapolk decimal poses 2026-10-09 · packet · register

  16. 2026-10-10 published T-146 · cases 102, 103

    Exact rational certificates at fifteen counts from Evan Daniel's regularized record lists

    upper bound confirmed

    Daniel after Xu, Chaoweeraprasit, Mishapolk, Levy · Daniel regularized lists 2026-10-10 · packet · register