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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

%I

%S 1,1,7,150,5857,363045,32817311,4078256168,667231014401,

%T 139047475691385,35961972186044999,11303290914120251574,

%U 4243674498966718214113,1875719852330658989518045,964140893268009386931042943,570249392860305817156465883040

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

%H Seiichi Manyama, <a href="/A305467/b305467.txt">Table of n, a(n) for n = 0..232</a>

%F a(n) ~ n! * n^n. - _Vaclav Kotesovec_, Jun 03 2018

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

%Y Main diagonal of A305466.

%Y Cf. A305465.

%K nonn

%O 0,3

%A _Seiichi Manyama_, Jun 02 2018

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Last modified September 18 16:10 EDT 2021. Contains 347527 sequences. (Running on oeis4.)