A305467 a(n) = Sum_{k=0..floor(n/2)} ((n-k)!/k!)*binomial(n-k,k)*n^(n-2*k)*(-1)^k.

1, 1, 7, 150, 5857, 363045, 32817311, 4078256168, 667231014401, 139047475691385, 35961972186044999, 11303290914120251574, 4243674498966718214113, 1875719852330658989518045, 964140893268009386931042943, 570249392860305817156465883040

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..232

Formula

a(n) ~ n! * n^n. - Vaclav Kotesovec, Jun 03 2018

Prog

(PARI) {a(n) = sum(k=0, n/2, ((n-k)!/k!)*binomial(n-k, k)*n^(n-2*k)*(-1)^k)}

Crossrefs

Main diagonal of A305466.

Cf. A305465.

Sequence in context: A152552 A349286 A308581 * A229806 A229880 A070248

Adjacent sequences: A305464 A305465 A305466 * A305468 A305469 A305470

Keyword

nonn

Author

Seiichi Manyama, Jun 02 2018

Status

approved