Superpermutation Almanac

Bounds

Pantone's bound

For every n ≥ 8, S(n) \ge n! + (n-1)! + (n-2)! + n - 3 + \left\lceil \frac{2(n-2)! - 2(n-2) - 4p_n/t_n}{n^2 - 4n + 1 - 2(n-1)/t_n} \right\rceil

For n = 8 to 12, (pₙ, tₙ) = (10, 46/3), (15, 287/12), (521/80, 359/40), (21, 263/12), (28, 195/4). For n ≥ 13, write n − 1 = 3m + r. If r = 0, (pₙ, tₙ) = (2m + 1/2 + 1/(4R₀), 4m − 3 − 1/(2R₀)); if r = 1, (m(2m + 1), 2m² + 2m − 2 − 1/R₁); if r = 2, ((m + 1)(2m + 1), 4m² + 5m − 5/2). R₀ = 2(n − 1)/7 if 7 divides n − 1, else u(n − 1 − u) with 7u ≡ 1 mod n − 1. R₁ is an LCM of cycle lengths set by m mod 6 (see the paper).

Holds for
n ≥ 8
Announced
Oct 29, 2026
Proof
Lean proof
Coefficient of (n−3)!
0

By Jay Pantone jaypantone.

Values

nAt least
846,130
9408,469
104,033,374
1143,917,903
12522,622,380
136,746,626,531
1493,891,141,149

Evidence

Proof checks

statement reviewed

Checked
Oct 29, 2026
Lean version
leanprover/lean4:v4.35.0
Mathlib commit
56a005855ea17e0b0958f73ec801ae140b0a1679
lean
v4.35.0
lean4checker
lean4-bundled@eb6cafb7290e8bd5f2937522d8d804f58f02bafc
nanoda
lean4-bundled@eb6cafb7290e8bd5f2937522d8d804f58f02bafc

build 993 s, peak 7.5 GB

Statement reviewed, not matched to a fixed statement. Checked statement and definitions.

Result 1 of batch L-0015, theorem general_lower, checked in attempt 1: AlmanacSolution.lean, line 10.

Repository at the checked commit · Repository archive (17.6 MB)

The judge checks each proof with two kernels. A fixed statement is also compared with the Almanac’s definitions; a custom statement is reviewed by hand.