cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

1, 1, 7, 150, 5857, 363045, 32817311, 4078256168, 667231014401, 139047475691385, 35961972186044999, 11303290914120251574, 4243674498966718214113, 1875719852330658989518045, 964140893268009386931042943, 570249392860305817156465883040
Offset: 0

Views

Author

Seiichi Manyama, Jun 02 2018

Keywords

Crossrefs

Main diagonal of A305466.
Cf. A305465.

Programs

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

Formula

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