T-090: Mixed rectangle-measure lower bounds verified at 17 counts in n=42…96

V3 C3 lower bound confirmed

2026-10-04 published · wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · 17 cases, n=42 to 96

Sixteen rectangle densities of wand125/square-packing-bounds, checked at coverage one and published on 3 and 4 October 2026, prove s(42)≥2739/400 = 6.8475, s(43)≥2763/400 = 6.9075, s(44)≥2789/400 = 6.9725, s(51)≥747/100 = 7.47, s(56)≥3121/400 = 7.8025, s(57)≥3149/400 = 7.8725, s(67)≥339/40 = 8.475, s(69)≥431/50 = 8.62, s(72)≥219/25 = 8.76, s(75)≥447/50 = 8.94, s(84)≥3763/400 = 9.4075, s(86)≥9503/1000 = 9.503, s(88)≥769/80 = 9.6125, s(93)≥247/25 = 9.88, s(94)≥497/50 = 9.94 and s(95)≥1993/200 = 9.965. A packing of n + 1 squares contains one of n, so the n=95 value also bounds n=96, where it is above the verified bound the record held: 17 counts in all.

Each is a density of 358 to 630 uniform rectangles in D4 orbits and no point mass, of total mass n - 1/100000, at core side 9977/10000 on 201 net half-angles of step 83/40000, of the kind and checker of T-082. The source reports each accepted at all 200 oblique net angles by code/mixed_rotated_verify.cpp, its research copy of Tokoharu's verify.cpp at coverage threshold one, and at the axis by exact integer tables. Nine supersede the source's certificates at the same count: eight of T-082's, and at n=84 T-071's. At the other seven they are the source's first mixed certificates.

All 16 values were above what the record reported at their counts, by 0.003 to 0.0375: over T-082 at eight counts, T-071 at n=84, and the source's rectangle certificates (T-046, T-068, T-077) at seven. At n=88 and 94 the source's certificates of later that day (T-091) are higher, and at n=67 and 84 those of 5 October (T-094), each verified here, so the verified lower bound there is theirs. Over the verified lower bounds they replace, at the other twelve counts and at n=96, the rise is 0.005 to 0.1175.

Each certificate was decided here on 6 October 2026 by sqverify-fast, this repository's clean-room measure verifier, at all 201 net directions of the retained candidate, and two mutants of each scaled below coverage one were refused: confirmed, independently re-implemented. The verifier shares no code with the source's checker and runs the same net-and-shrink method, so it is a second implementation and not a second method. The source's own checker was not run here.

wand125 after Tokoharu and Levy, square-packing-bounds. Registration was requested in 16 comments of 3 and 4 October 2026 on jlevy/squares#282. The source says parts of the work were produced with AI assistance under human direction.

Significance, composition and next rung
Significance
The strongest verified lower bounds on record at 13 counts from n=42 to 96, and the strongest reported at 12 of its own. Further sizes from the generator and checker of T-069, T-071, T-072, T-075 and T-082, with no new technique, at S3 as those are; the 5 October review of these certificates confirmed S3.
Composition
16 primary certificates, each on its own reported entry and its own replay entry. n=96 takes the n=95 certificate directly, its mass being below that count, so no step is added. Each replay is sqverify-fast at all 201 net directions of the retained candidate: one interval-certified method, replayed here by an independent implementation, C3. The source's checker and axis tables were not run here, so no second method and no reproduction with the producer's code stands beside it.
Next rung
V4 and C4 need a human oversight record and two adversarial AI reviews of the claim by distinct reviewers: the 5 October review of these certificates is one, and the review of the census route of the same day decided the route, not these certificates' mathematics. Replays of the source's own checker (about 146 CPU-hours planned, devtools.audit_wand125_point_and_mixed mixed-shard wand125-mixed-bounds-2026-10-04 --runners 8) would add a reproduction with the producer's code beside the rung; a second machine method would be a method-distinct decision of rotated coverage.
Novelty
previously-published Present in an identified source

The cases

This result concerns 17 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
426.84750070.1525open=frontier n-042.md
436.9075000.0925frontier n-043.md
446.9725000.0275frontier n-044.md
517.4700007.6903560.22035593…frontier n-051.md
567.80250080.1975frontier n-056.md
577.8725000.1275frontier n-057.md
678.4800008.7071070.22710678…frontier n-067.md
698.6200008.8271950.20719465…frontier n-069.md
728.76000090.24frontier n-072.md
758.9400000.06frontier n-075.md
849.4110009.6980530.28705206…frontier n-084.md
869.5030009.8205660.31756573…frontier n-086.md
889.6200009.8824520.26245103…frontier n-088.md
939.880000100.12frontier n-093.md
949.9500000.05frontier n-094.md
959.9650000.035frontier n-095.md
969.9700000.03frontier n-096.md

Results on these cases

28 results in the register on these cases, oldest first
  1. 2005 published T-007 · 17 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-081 (reported), T-082, T-090, T-091 and T-094

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085 · 17 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. 2026-09-22 published T-044 · cases 56, 57, 69, 72

    Weighted point lower bounds for ten counts in n=26…72, plus seven from the same files

    lower bound confirmed superseded by T-090

    wand125 after Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point bounds 2026 · packet · source · review · register

  4. 2026-09-24 published T-088 · case 69

    s(69)≤8.82719465572975, Ellsworth's degree-38 packing, certified exactly from its picture

    upper bound confirmed superseded by T-101

    Ellsworth after hmbelvedere, Cantrell, Schadt, Morandi · Ellsworth n69 2026-09-24 · packet · packet · register

  5. 2026-09-27 published T-045 · case 75

    Rectangle-density lower bounds replayed at 15 counts in n=18…78

    lower bound confirmed superseded by T-090

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · packet · packet · source · review · register

  6. 2026-09-27 published T-046 · 14 of these cases

    Rectangle-density lower bounds reported for 48 counts in n=18…95

    lower bound recorded superseded by T-090, T-091 and T-094

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · wand125 rectangle bounds 2026-09-28 · packet · packet · register

  7. 2026-09-28 published T-048 · case 51

    s(50)≥37/5=7.4

    lower bound confirmed on these cases, superseded by T-090

    wand125 after Daniel, Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point and mixed bounds 2026-09-28 · packet · source · review · register

  8. 2026-09-28 published T-070 · 10 of these cases

    Rectangle-density lower bounds replayed at 25 counts in n=29…95

    lower bound confirmed superseded by T-090 and T-094

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · register

  9. 2026-09-29 published T-058 · 17 of these cases

    Rectangle-certificate ceiling α·UB(n) proved for n=1..100; B·UB(n) on 64 grid rows

    method limit confirmed

    wand125 after Tokoharu, Daniel · wand125 tools 2026 · packet · register

  10. 2026-09-29 published T-083 · 17 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-081 (reported), T-082, T-090, T-091 and T-094

    Karakuş · Karakuş 2026 · source · register

  11. 2026-10-01 published T-068 · 11 of these cases

    Rectangle-density lower bounds verified at 34 counts in n=19…95

    lower bound confirmed on these cases, superseded by T-090 and T-091

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · source · review · register

  12. 2026-10-01 published T-074 · 11 of these cases

    Rectangle-density lower bounds replayed at 31 counts in n=19…95

    lower bound confirmed on these cases, superseded by T-090 and T-091

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · packet · source · review · register

  13. 2026-10-02 published T-071 · cases 84, 86

    Mixed rectangle-measure lower bounds replayed at n=84…87

    lower bound confirmed superseded by T-090 and T-094

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

  14. 2026-10-02 published T-075 · cases 86, 88, 93, 96

    Mixed rectangle-measure lower bounds replayed at nine counts in n=83…96

    lower bound confirmed on these cases, superseded by T-081 (reported), T-082, T-090 and T-091

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds afternoon 2026-10-02 · packet · source 1 · source 2 · review · register

  15. 2026-10-02 published T-077 · case 42

    Rectangle-density lower bounds replayed at n=20, 42 and 70

    lower bound confirmed superseded by T-090

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-02 · packet · packet · source 1 · source 2 · review 1 · review 2 · register

  16. 2026-10-03 published T-081 · case 96

    s(k2−4)=k for every integer k from 5 up; k=5…18 are the cases held here

    optimality reviewed

    Daniel after Burns, Massaccesi · evand square-packing 2026-10-03 · packet · packet · source · review · register

  17. 2026-10-03 published T-082 · 9 of these cases

    Mixed rectangle-measure lower bounds verified at 22 counts in n=51…96

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-03 · packet · packet · source · review · register

  18. 2026-10-04 published T-090 this result · 17 of these cases

    Mixed rectangle-measure lower bounds verified at 17 counts in n=42…96

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-04 · packet · source · review · register

  19. 2026-10-04 published T-091 · 5 of these cases

    Mixed rectangle-measure lower bounds verified at 17 counts in n=53…95

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds evening 2026-10-04 · packet · source · review · register

  20. 2026-10-05 published T-094 · cases 67, 84

    Mixed rectangle-measure lower bounds verified at n=67 and 84

    lower bound confirmed

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-05 · packet · source · review · register

  21. 2026-10-05 published T-101 · cases 51, 69, 88

    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

  22. 2026-10-07 published T-116 · case 88

    s(n)≤Sn at nine counts, from the second SQUISH update’s new rational packings

    upper bound confirmed on these cases, superseded by T-127

    Chaoweeraprasit after Ellsworth, Couzo and SQUISH · SQUISH second update 2026-10-07 · packet · register

  23. 2026-10-07 published T-124 · 11 of these cases

    Reported non-strict local minima for 178 source configurations

    restricted optimality recorded

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

  24. 2026-10-08 published T-125 · cases 51, 84, 86, 88

    Complete rational construction reports at 25 counts

    upper bound confirmed

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

  25. 2026-10-08 published T-126 · case 51

    Undilated n51 construction over Q(sqrt2)

    upper bound confirmed

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

  26. 2026-10-08 published T-127 · case 88

    Fourteen rational refinements, seventeen complete source cases

    upper bound confirmed

    Gupta after Chaoweeraprasit, Daniel · Gupta rational refinements 2026-10-08 · packet · register

  27. 2026-10-08 published T-130 · cases 84, 86

    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

  28. 2026-10-09 published T-138 · cases 84, 86

    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