Number of permutations p of [2n] having no index i with |p(i)-i| = n.
A306535
Number of permutations p of [2n] having no index i with |p(i)-i| = n.
Terms
- a(0) =1a(1) =1a(2) =9a(3) =265a(4) =14833a(5) =1334961a(6) =176214841a(7) =32071101049
External references
- oeis: A306535