Tail/arc-compression threshold sweep. Started from the compact size-32 >N/2 core. Direct insertion and exhaustive 1→2 were rigid at N/2, 2N/5, N/3, and N/4. Relaxing to the N/3-tail and following a deeper deletion/refill branch exposed the effective 2→3 exchange {1820,2352}→{1297,1805,2932}, yielding size 33. Final min(A)=1297≈0.3913N, so the whole new record remains well above N/3.
Yongxi (Aaron) Lin · 2026-08-10 07:42:49 UTC