T-199: Daniel's smaller n229 update, replacing the opening certificate

V3 C3 Upper bound confirmed superseded by T-225

2026-10-18 published · Daniel after Couzo, de Winter, Levy · n=229

One complete rational source certificate reports a finite upper-bound improvement at the exact side it states: s(229)≤7825080756947776580756939951343/500000000000000000000000000000.

The certificate and its duplicate-square and outside-container controls were decided here on 19 October 2026 by both maintained exact routes, and the frozen comparison rebuilt; no route here is the source's code, so the replay is independently re-implemented. The 19 October review found no blocking defect.

The 18 October comment on issue 674 asks that this smaller certificate be registered in place of the opening value (T-198), which stays registered as the earlier report. The source states it is a dilation of a binary64 packing by 1 + 10^-12 with rational half-angle tangents, a nearby configuration of the opening packing with the same tilted structure, and credits Couzo's #672 packing, which refines de Winter's #668, as the start. The issue says the work was done with Claude (Claude Code) under Daniel's direction.

Significance, composition and next rung
Significance
The same arrangement family, 1.32e-05 below T-196 and 1.74e-06 below T-198; no lower bound or optimum.
Next rung
None for the bound. V4 and C4 need a second accepted adversarial review by a distinct reviewer and a retained human oversight record; one AI review, of 19 October, is retained.
Novelty
previously-published Present in an identified source

The case

Case record
Regularized by the Squares Project with Daniel's regularizer (evand/square-packing, MIT)
As published
The packing as published, Daniel 2026 [Daniel regularized lists 2026-10-20]

n=229

15.1315.650
151617
15.13316.133
nn+1

Proven

15.13728≤s(229)≤15.650162

  • exact

Citation record n-229

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

upperDaniel 2026, GitHub (confirmed T-225)

Open

  • optimality

The case record

Results on the case

11 results in the register on n=229, oldest first, each with what it established and how it stands now.

  1. 2005 published T-007

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

    V0 C1 Lower bound incomplete on this case, superseded by T-083

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085

    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. 2026-09-29 published T-083

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

    V3 C3 Lower bound confirmed

    Karakuş · Karakuş 2026 · source · register

  4. 2026-10-05 published T-101

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

    V3 C3 Upper bound confirmed on this case, superseded by T-225

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

  5. 2026-10-12 established T-155

    Exact regularized sides at 59 counts, 5.4e-20 to 9.9e-15 below the ceilings they replace

    V3 C3 Upper bound confirmed on this case, superseded by T-225

    Levy after Daniel · register

  6. 2026-10-13 published T-180

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

    V0 C1 Lower bound reviewed on this case, superseded by T-083

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

  7. 2026-10-17 published T-196

    de Winter reports three smaller rational upper bounds at 227, 229 and 260

    V3 C3 Upper bound confirmed superseded by T-225

    de Winter after Levy · de Winter upper bounds 2026-10-17 · packet · register

  8. 2026-10-17 published T-198

    Daniel's opening n229 dilation certificate, after Couzo and de Winter

    V3 C3 Upper bound confirmed superseded by T-225

    Daniel after Couzo, de Winter, Levy · Daniel n229 dilation 2026-10-17 · packet · register

  9. 2026-10-17 published T-227

    Couzo's refinements of de Winter's 227 and 229, below T-196 at both

    V0 C0 Upper bound recorded superseded by T-225

    Couzo after de Winter, Daniel, Levy · Couzo issue 672 2026-10-17 · packet · packet · register

  10. 2026-10-18 published T-199 this result

    Daniel's smaller n229 update, replacing the opening certificate

    V3 C3 Upper bound confirmed superseded by T-225

    Daniel after Couzo, de Winter, Levy · Daniel n229 dilation update 2026-10-18 · packet · register

  11. 2026-10-20 published T-225

    Daniel's solved, regularized views at 204, 227, 229 and 260, each the smallest side reported there

    V3 C3 Upper bound confirmed

    Daniel after Couzo, de Winter, Polkovskyi, Levy · Daniel regularized lists 2026-10-20 · packet · register