A306267 Number of permutations of [n] within distance floor(n/2) of a fixed permutation.

1, 1, 2, 3, 14, 31, 230, 675, 6902, 25231, 329462, 1441923, 22934774, 116914351, 2193664790, 12764590275, 276054834902, 1805409270031, 44222780245622, 321113303226243, 8787513806478134, 70146437009397871, 2121181056663291350, 18462286083671614275

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..475

Formula

a(n) = A306209(n,floor(n/2)).

Crossrefs

Cf. A306209.

Shifted bisections give: A048163 (even part), A092552 (odd part).

Sequence in context: A047005 A338513 A080017 * A042551 A296149 A355176

Adjacent sequences: A306264 A306265 A306266 * A306268 A306269 A306270

Keyword

nonn

Author

Alois P. Heinz, Feb 01 2019

Status

approved