T-040: s(17)>232001/50000=4.64002

V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

2026-09-26 published · Overbeck after Levy, Mira-acc, Guzhou0806 · n=17

s(17)>232001/50000 = 4.64002, by Overbeck's 17-squares-certified-bound v1.1.0 release of 26 September 2026. It raised the verified bound by exactly 1/50 over R052 (T-039).

It widens v1.0.0's charge with weighted-threshold features (coefficients 2, 1, 1, 1 at threshold 3) and pairwise-intersecting winning-subset features, every distinct rule of capacity one: 280 point, 155 two-of-three, 26 three-of-five, one four-of-seven, 54 weighted and 30 winning-subset orbits over 2,048 parent-angle intervals, with parents of side 32950/33143 in the container 4613/1000. Seventeen cores at the minimum core charge 998727933 exceed the budget 16978369232 (units of 10^-9) by 5629.

It was replayed here in full on 27 September 2026 by the source's launcher, running its Python and JavaScript BigInt checkers over every interval; they agree with each other and with all three published ledger pairs, and they are one event-cell method.

Overbeck, 17-squares-certified-bound, building on Squares Project (Levy), Mira and Guzhou0806, as its ATTRIBUTION.md states. Its AUTHORS.md names Overbeck as Kleddamag and says the work was produced with AI agents (OpenAI Codex) under his direction.

Significance, composition and next rung
Significance
Raised the verified lower bound at n=17 by 0.02, with T-041's 0.01999 the largest step of the ladder after R012's 0.02305, and it is the release that introduced the weighted-threshold and winning-subset charge features that 4.66001, R067 and R068 reuse. S3 by the T-015 and T-032 precedent, a result by others scored as its claim would be from anyone. Confirmed on 11 October: the features could argue for S4's reusable technique, but they have been reused at n=17 alone (T-041, T-043, T-093), one case's ladder, as T-133's transfer and T-145's kernel are one count and not yet a family (S3 with the technique noted); T-047's certificate kind, reused across n=18 to 126, is what a reusable technique at S4 looks like here.
Next rung
V4 and C4 need two adversarial AI reviews by distinct reviewers and a human oversight record, and none is retained. 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; extending it to them is the reachable second machine method. The only packing/tests control is the retention check of the packet's compressed files; the adversarial control is the source's controls.py, replayed here (eight corrupted certificates rejected by both checkers). Rung 5 needs a proof-assistant formalization reviewed by human experts. Superseded as the verified lower bound on 2026-09-27 by Overbeck's 466001/100000 (T-041); stays true as stated.
Novelty
previously-published Present in an identified source

The case

Case record

n=17

4.664.676
456
4.1235.123
nn+1

Proven

4.66044≤s(17)≤4.675531

  • exact

Citation record n-017

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

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

Open

  • optimality

The case record

Results on the case

19 results in the register on n=17, 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-093 and T-153 (reported)

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-08-21 published T-015

    s(17)≥22529/5000=4.5058

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Massaccesi after Burns · Burns–Massaccesi n17 · packet · register

  3. 2026-08-31 established T-001

    s(17)≥4426213/1000000=4.426213, from a sixteen-point unavoidable set

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Levy after Bentz · register

  4. 2026-08-31 established T-003

    The sixteen-point set's unavoidability ceiling lies in [4426213/1000000,4427/1000)

    V3 C3 Method limit confirmed

    Levy after Bentz · register

  5. 2026-09-04 established T-019

    s(n)≥459/100=4.59 for n=17,18,19

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Levy after Burns, Massaccesi · register

  6. 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

  7. 2026-09-20 published T-032

    s(17)≥461300/99999=4.61304613…, and beneath it Mira's s(17)≥4613/1000

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Guzhou0806, Mira-acc after Levy, Burns, Massaccesi · n17 weighted certificates 2026-09-20 · packet · register

  8. 2026-09-21 published T-038

    s(17)>461300/99853=4.6197910929…

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Overbeck after Levy, Mira-acc, Guzhou0806 · Kleddamag n17 certified bound · packet · source · review · register

  9. 2026-09-21 published T-065

    s(17)≤4.6755300936045509…, Bidwell's packing certified exactly

    V3 C3 Upper bound confirmed

    Overbeck after Levy, Mira-acc, Guzhou0806 · Kleddamag n17 certified bound · packet · source · review · register

  10. 2026-09-25 published T-039

    s(17)>231001/50000=4.62002

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Guzhou0806 after Overbeck, Mira-acc, Levy · Guzhou0806 n17 R052 · packet · source · review · register

  11. 2026-09-26 published T-040 this result

    s(17)>232001/50000=4.64002

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Overbeck after Levy, Mira-acc, Guzhou0806 · Kleddamag n17 4.640020 · packet · source · review · register

  12. 2026-09-27 published T-041

    s(17)>466001/100000=4.66001

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Overbeck after Levy, Mira-acc, Guzhou0806 · Kleddamag n17 4.66001 · packet · source · review · register

  13. 2026-09-28 published T-042

    s(17)>233009/50000=4.66018

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Guzhou0806 after Overbeck, Mira-acc, Levy · Guzhou0806 n17 R067 · packet · source · review · register

  14. 2026-09-28 published T-043

    s(17)>116511/25000=4.66044

    V3 C3 Lower bound confirmed superseded by T-093 and T-153 (reported)

    Guzhou0806 after Overbeck, Mira-acc, Levy · Guzhou0806 n17 R068 · packet · source · review · register

  15. 2026-09-29 published T-058

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

    V3 C3 Method limit confirmed

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

  16. 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 on this case, superseded by T-093 and T-153 (reported)

    Karakuş · Karakuş 2026 · source · register

  17. 2026-09-30 published T-093

    s(17)>18641771/4000000=4.66044275

    V3 C3 Lower bound confirmed

    Guzhou0806 after Overbeck, Mira-acc, Levy · Guzhou0806 n17 R071 · packet · source · review · register

  18. 2026-10-12 published T-153

    Candidate proof that Bidwell's 1998 packing is optimal, s(17)=4.67553009360455…

    V0 C1 Optimality reviewed

    Overbeck after Levy, Ahmed, Mira-acc, Guzhou0806, Maaz · Overbeck n17 candidate 2026 · packet · register

  19. 2026-10-12 published T-154

    Fitzharding reports a Lean proof that s(17)=4.67553009360455…

    V3 C1 Formalization reviewed

    Fitzharding after Levy, Ahmed, MacIver · Fitzharding n17 Lean 2026 · packet · source · source build receipt · review 1 · review 2 · register