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A305467
a(n) = Sum_{k=0..floor(n/2)} ((n-k)!/k!)*binomial(n-k,k)*n^(n-2*k)*(-1)^k.
3
1, 1, 7, 150, 5857, 363045, 32817311, 4078256168, 667231014401, 139047475691385, 35961972186044999, 11303290914120251574, 4243674498966718214113, 1875719852330658989518045, 964140893268009386931042943, 570249392860305817156465883040
OFFSET
0,3
LINKS
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
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jun 02 2018
STATUS
approved