T-141: Exact rational certificates at 132 and 308 from Daniel's third record hunt

V3 C3 Upper bound confirmed superseded by T-174 and T-221

2026-10-10 published · Daniel after Fang, Arslanov, Mustafin, Shangitbayev, Couzo, Levy · n=132,308

Two complete rational source certificates by Daniel, reported on jlevy/squares#489, prove finite upper bounds at the exact sides they state: s(132)≤11.985680198845808811522231964102 and s(308)≤17.998269879526255875387992744507.

The same release states s(343)≤18.978232523635611279730512106023 and s(344)≤18.994450514277401521114135796864, beyond the case corpus; the source register tracks those as beyond-horizon rows, proved by the same evidence.

Each certificate gives a rational side and, for each unit square, a rational centre and the tangent of its half-angle, in Daniel's format, each side printed in full. The author reports that his two exact rational checkers, verify_cert.py and verify_cert2.py, with different geometry, pass all four, with least certified clearances of 1e-20 for pairs and 5e-21 for walls. Each side is an 80-digit KKT point with positive multipliers on the load-bearing contacts, a reduced Hessian positive semidefinite modulo exact flat motions and a jammed first-order MILP in every corner-corner branch; those are numerical evidence, as the source says, not proofs.

All 15 retained jobs of the release's five-count replay, the four positives with their duplicate-square and outside-container controls among them, were decided again here on 10 October 2026 by both maintained exact routes and equal their retained rows, and a third exact route, half-extent containment and exact intersection area, decided the four with six controls each. No route here is the source's code, so the replay is independently re-implemented. The 10 October review found no blocking defect.

Each side was below the ceiling its case held, at 308 the grid's 18. On 11 October 2026 the case records adopted both as the house.

Credit Daniel (https://github.com/evand/square-packing), whose quality-diversity basin explorer with a two-parent crossover move found all four. The packings at 308, 343 and 344 build on Fang's packings from issue 484 in the Arslanov-Mustafin-Shangitbayev two-wedge family, and the author asks that the construction be credited to him: 344 is his packing polished and moved by a corner-corner descent, 308 his packing polished and moved seven explorer steps, and 343 his 344 less one square, in a different basin from his 343. The packing at 132 is the author's own lineage from issue 465. The search code and the request were written with Claude under the author's direction.

Significance, composition and next rung
Significance
Smaller finite construction sides at n=132 and 308, 1.73e-03 to 5.65e-03 below the case ceilings; no lower bound or optimum.
Next rung
V4 and C4 need a retained human oversight record: two accepted adversarial reviews by distinct AI reviewers are retained, the 10 October review and the 11 October final review (docs/project/reviews/review-2026-10-11-final-upper-bounds.md).
Novelty
previously-published Present in an identified source

The cases

Case record

n=132

11.5111.986
111213
11.48912.489
nn+1

Proven

11.51135≤s(132)≤11.985681

  • exact

Citation record n-132

lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)

upperDaniel & PingYou Ltd, GitHub (confirmed T-174)

Open

  • optimality

The case record

LowerUpper
Gap0.47432242…
Case record
Regularized by the Squares Project with Daniel's regularizer (evand/square-packing, MIT)
As published
The packing as published, Daniel 2026 [Daniel n308 2026-10-19]

n=308

17.5617.997
171819
17.55018.550
nn+1

Proven

17.56604≤s(308)≤17.997150

  • exact

Citation record n-308

lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)

upperDaniel 2026, GitHub (confirmed T-221)

Open

  • optimality

The case record

LowerUpper
Gap0.43110095…

Results on these cases

15 results in the register on n=132,308, oldest first, each with what it established and how it stands now.

  1. 2005 published T-007 · n=132,308

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

    V0 C1 Lower bound incomplete on these cases, superseded by T-083 and T-180 (reported)

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085 · n=132,308

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

    V3 C3 Correction confirmed

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

  3. 2026-09-27 published T-056 · n=132

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

    V3 C3 Upper bound confirmed superseded by T-174

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

  4. 2026-09-29 published T-083 · n=132,308

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

    V3 C3 Lower bound confirmed

    Karakuş · Karakuş 2026 · source · register

  5. 2026-10-05 published T-098 · n=132

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

    V3 C3 Upper bound confirmed on these cases, superseded by T-174

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

  6. 2026-10-07 published T-124 · n=308

    Reported non-strict local minima for 178 source configurations

    V0 C0 Restricted optimality recorded

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

  7. 2026-10-09 published T-131 · n=132

    s(132)≤11.987099332245063… from Daniel's record hunt

    V3 C3 Upper bound confirmed superseded by T-174

    Daniel after Couzo, Chaoweeraprasit, Levy · Daniel record hunt 2026-10-09 · packet · register

  8. 2026-10-09 published T-134 · n=132

    Six exact rational certificates from Couzo

    V3 C3 Upper bound confirmed on these cases, superseded by T-174

    Couzo after Polkovskyi, Chaoweeraprasit, Gupta, Xu, Daniel, Ellsworth, Levy · Couzo exact certificates 2026-10-09 · packet · register

  9. 2026-10-09 published T-138 · n=132

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

    V3 C3 Upper bound confirmed superseded by T-174

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

  10. 2026-10-10 published T-135 · n=308

    A packing of 308 squares below the grid, from Fang

    V3 C3 Upper bound confirmed superseded by T-221

    Fang after Arslanov, Mustafin, Shangitbayev, Ellsworth, Stead · Fang two-wedge certificates 2026-10-10 · packet · register

  11. 2026-10-10 published T-140 · n=132

    Six more exact rational certificates from Couzo

    V3 C3 Upper bound confirmed superseded by T-174

    Couzo after Chaoweeraprasit, Polkovskyi, Xu, Daniel, Ellsworth, Levy · Couzo certificates 2026-10-10 · packet · register

  12. 2026-10-10 published T-141 this result · n=132,308

    Exact rational certificates at 132 and 308 from Daniel's third record hunt

    V3 C3 Upper bound confirmed superseded by T-174 and T-221

    Daniel after Fang, Arslanov, Mustafin, Shangitbayev, Couzo, Levy · Daniel record hunt 3 2026-10-10 · packet · register

  13. 2026-10-13 published T-174 · n=132,308

    Tighter certificates at 68 counts from PingYou Ltd, of others' packings and its own

    V3 C3 Upper bound confirmed

    PingYou Ltd after Friedman, Ellsworth, Daniel, Xu, Barnett, Couzo, Ostashev, Chaoweeraprasit, Gupta, Fang, Polkovskyi, Levy · PingYou PR 574 certificates 2026-10-13 · packet · register

  14. 2026-10-13 published T-180 · n=132,308

    Closed-form lower bound s(N)≥a(N) for every non-square N≥49, reported

    V0 C1 Lower bound reviewed

    Hosono · wand125 closed form 2026-10-14 · packet · packet · register

  15. 2026-10-19 published T-221 · n=308

    Daniel's smaller n308 packing, started from Chaoweeraprasit's 307 packing, certified exactly

    V3 C3 Upper bound confirmed

    Daniel after Chaoweeraprasit, Levy · Daniel n308 2026-10-19 · packet · register