T-056: Smaller packings for 49 counts from n=68 to 307, each certified two independent ways

V3 C3 upper bound confirmed superseded by T-098, T-113, T-115, T-116, T-117, T-118, T-119, T-125 and T-127

2026-09-27 published · Couzo · 49 cases, n=68 to 307

For each of 49 counts n from 68 to 307, s(n) is at most the verified upper bound its case record carries, from Francisco Couzo's packings as published on 27 September 2026. The counts are 68, 102, 103, 105, 106, 110, 123, 130, 131, 132, 152, 154, 155, 156, 172, 177, 180, 181, 182, 199, 206 to 210, 228, 236 to 241, 259, 263, 268 to 273, 292, 297 and 301 to 307.

Each bound is the side the source prints, from 8.798795237222592 at n=68 to 17.981030548643712 at n=307, or, where the printed pose's own side rounds up past it, that side plus one unit of its fifteenth decimal at 26 counts and 2, 3 and 2 units at n=206, 259 and 305. Every printed side is below the best known side this project recorded before, by 3.0e-8 at n=172 up to 0.022 at n=301, and below the live catalogue of 29 September 2026.

Each bound is certified here twice, by methods that share no geometry code. The first is an exact rational packing, the source's decimal pose rounded to rationals at centre dilation 1, decided pair by pair and wall by wall over Q by two checkers that share no code. The second is outward-rounded interval arithmetic on the source's own pose as printed, with the true cosine and sine of each angle, which decides every pair and wall at 40 digits and encloses the pose's extent to within 1e-39.

Francisco Couzo, franciscouzo/square-packing. The author said on jlevy/squares#227 that he found the 102 and 103 packings "with the help of Claude", and the repository itself states no AI assistance.

Significance, composition and next rung
Significance
Forty-nine substantive case results at once: each moves the best known side at its count, 28 of them by more than 0.001, and each moves this repository's verified ceiling off the integer grid onto a certified packing, so 46 cases stop trailing their report. S3 by the anchor "a substantive case result"; the source publishes no method, so nothing here is a reusable technique.
Composition
Both machine entries decide all 49 bounds, each at its case's verified value, by different methods (exact-algebraic on a rational rounding of each pose; interval-certified on the printed pose), so every load-bearing part is C3, with two machine methods shown beside the rung. Their common mode is stated in E-franciscouzo-2026-09-27-interval-replay. The comparisons with earlier sides and the live catalogue are recorded values and set no rung.
Next rung
V4 and C4 need two adversarial AI reviews by distinct reviewers of the complete claim and a human oversight record; the two reviews so far, of 2026-09-29 and 2026-09-30, are same-project reviews of each route and are not recorded in this entry's reviews. At n=206, 259 and 305 both routes refute the printed side for the printed pose, so the printed side itself needs a different pose, refined beyond the source's binary64 digits, or coordinates the source prints at higher precision; that would be a new packing, not a replay.
Novelty
previously-published Present in an identified source

The cases

This result concerns 49 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
688.5100008.7987960.28879523…open=frontier n-068.md
10210.28000010.6058290.32582869…frontier n-102.md
10310.6792330.39923204…frontier n-103.md
10510.7906770.51067657…frontier n-105.md
10610.31070810.8229090.51219960…open≈frontier n-106.md
11010.51249210.9967840.48429119…frontier n-110.md
12311.09481011.5913790.49656809…open=frontier n-123.md
13011.42016411.9044840.48431819…frontier n-130.md
13111.46585611.9511510.48529394…frontier n-131.md
13211.51135711.9913280.47997011…open≈frontier n-132.md
15212.34271912.8307190.48799951…frontier n-152.md
15412.42686012.9265630.49970180…open=frontier n-154.md
15512.46870912.9525040.48379399…frontier n-155.md
15612.51041212.9820830.47167054…open≈frontier n-156.md
17213.11942913.6189890.49955949…frontier n-172.md
17713.31600513.8229800.50697411…frontier n-177.md
18013.43251713.9176540.48513626…open=frontier n-180.md
18113.47112113.9537490.48262705…open≈frontier n-181.md
18213.50961113.9740910.46447888…frontier n-182.md
19914.11065714.6175730.50691458…open=frontier n-199.md
20614.36542414.8601590.49473403…open≈frontier n-206.md
20714.40143814.8879930.48655348…open=frontier n-207.md
20814.43735914.9245190.48715890…frontier n-208.md
20914.47318814.9496180.47642933…frontier n-209.md
21014.50892514.9730020.46407539…open≈frontier n-210.md
22815.10308115.6046030.50152058…frontier n-228.md
23615.37447415.8678010.49332605…open=frontier n-236.md
23715.40805115.9036770.49562471…frontier n-237.md
23815.44155215.9261470.48459405…frontier n-238.md
23915.47497915.9493140.47433403…frontier n-239.md
24015.50833115.9696860.46135431…open≈frontier n-240.md
24115.54160815.9881330.44652348…frontier n-241.md
25916.09647316.6025690.50609453…frontier n-259.md
26316.22418516.7404200.51623448…open=frontier n-263.md
26816.38238016.8788150.49643464…open≈frontier n-268.md
26916.41383016.9059680.49213659…frontier n-269.md
27016.44521816.9378080.49258850…open=frontier n-270.md
27116.47654516.9508210.47427548…open≈frontier n-271.md
27216.50781016.9681110.46029955…open=frontier n-272.md
27316.53901416.9839260.44491103…open≈frontier n-273.md
29217.09066017.5972500.50658936…open=frontier n-292.md
29717.24066917.7404180.49974824…open≈frontier n-297.md
30117.35971517.8466680.48695189…frontier n-301.md
30217.38934517.8813070.49196046…open=frontier n-302.md
30317.41892417.9203130.50138805…frontier n-303.md
30417.44845117.9346510.48619876…open≈frontier n-304.md
30517.47792617.9529600.47503261…frontier n-305.md
30617.50735117.9634390.45608678…frontier n-306.md
30717.53672517.9810310.44430551…frontier n-307.md

Results on these cases

37 results in the register on these cases, oldest first
  1. 2005 published T-007 · 49 of these cases

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

    lower bound incomplete

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085 · 49 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 · case 68

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

    lower bound confirmed superseded by T-068 and T-074

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

  4. 2026-09-27 published T-046 · case 68

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

    lower bound recorded superseded by T-068 and T-074

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

  5. 2026-09-27 published T-056 this result · 49 of these cases

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

    upper bound confirmed superseded by T-098, T-113, T-115, T-116, T-117, T-118, T-119, T-125 and T-127

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

  6. 2026-09-28 published T-070 · case 68

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

    lower bound confirmed superseded by T-068 and T-074

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

  7. 2026-09-29 published T-058 · case 68

    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

  8. 2026-09-29 published T-083 · 49 of these cases

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

    lower bound confirmed

    Karakuş · Karakuş 2026 · source · register

  9. 2026-10-01 published T-068 · case 68

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

    lower bound confirmed

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

  10. 2026-10-01 published T-074 · case 68

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

    lower bound confirmed

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

  11. 2026-10-02 published T-073 · cases 102, 103, 105

    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

  12. 2026-10-02 published T-080 · cases 102, 103, 105

    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

  13. 2026-10-03 published T-092 · 7 of these cases

    Smaller packings again at seven counts from n=208 to 306, each certified two independent ways

    upper bound confirmed superseded by T-098, T-113, T-116, T-119 and T-127

    Couzo · franciscouzo square-packing 2026-10-03 · packet · register

  14. 2026-10-05 published T-098 · 46 of these cases

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

    upper bound confirmed

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

  15. 2026-10-07 published T-113 · 7 of these cases

    s(n)≤Sn at ten counts, n=108 to 303, from new SQUISH rational packings

    upper bound confirmed

    Chaoweeraprasit after Ellsworth · SQUISH ten packings 2026-10-07 · packet · register

  16. 2026-10-07 published T-115 · 8 of these cases

    s(n)≤Sn at twelve counts, from the SQUISH update’s new and smaller rational packings

    upper bound confirmed

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

  17. 2026-10-07 published T-116 · 6 of these cases

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

    upper bound confirmed

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

  18. 2026-10-07 published T-117 · cases 105, 292

    Exact rational ceiling refinements at n=105, 292

    upper bound confirmed

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

  19. 2026-10-07 published T-118 · case 68

    Exact rational ceiling refinements at n=68

    upper bound confirmed

    Rehwaldt after Couzo and earlier contributors · Rehwaldt n68 refinement 2026-10-07 · packet · register

  20. 2026-10-07 published T-119 · cases 270, 272

    Three exact feasible upper bounds at n=266,270,272 from new source arrangements

    upper bound confirmed

    Daniel after Levy, Ellsworth, Couzo, Stead · Daniel new arrangements 2026-10-07 · packet · register

  21. 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

  22. 2026-10-07 published T-121 · case 106

    Reported s(106) ≤ alpha_106 with a degree-32 exact side form

    upper bound recorded

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

  23. 2026-10-07 published T-122 · case 152

    Reported s(152) ≤ alpha_152 with a degree-40 exact side form

    upper bound recorded

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

  24. 2026-10-07 published T-123 · case 177

    Reported s(177) ≤ alpha_177 with a degree-32 exact side form

    upper bound recorded

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

  25. 2026-10-07 published T-129 · cases 105, 130, 292

    Three dated Daniel certificate reports with historical source custody

    upper bound recorded superseded by T-117, T-125 and T-127

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

  26. 2026-10-08 published T-125 · 8 of these cases

    Complete rational construction reports at 25 counts

    upper bound confirmed

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

  27. 2026-10-08 published T-127 · 12 of these cases

    Fourteen rational refinements, seventeen complete source cases

    upper bound confirmed

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

  28. 2026-10-08 published T-128 · 6 of these cases

    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

  29. 2026-10-08 published T-130 · cases 105, 270

    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

  30. 2026-10-09 published T-131 · case 132

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

    upper bound confirmed

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

  31. 2026-10-09 published T-134 · 5 of these cases

    Six exact rational certificates from Francisco Couzo

    upper bound confirmed

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

  32. 2026-10-09 published T-136 · 15 of these cases

    Seventeen exact rational packings from SQUISH's third request

    upper bound confirmed

    Chaoweeraprasit after Couzo, Xu, Goebel, Schadt, Ellsworth, Hajba, Levy · SQUISH third request 2026-10-09 · packet · register

  33. 2026-10-09 published T-138 · 9 of these cases

    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

  34. 2026-10-10 published T-140 · 5 of these cases

    Six more exact rational certificates from Francisco Couzo

    upper bound confirmed

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

  35. 2026-10-10 published T-141 · case 132

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

    upper bound confirmed

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

  36. 2026-10-10 published T-144 · case 123

    Linear-measure lower bound s(n)≥563/50=11.26 for n=122…126, reported

    lower bound recorded

    wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear n122 2026-10-10 · packet · register

  37. 2026-10-10 published T-146 · 9 of these cases

    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