OFFSET
0,2
FORMULA
a(n) = (1/6) * Sum_{k=0..n} (k + 3)! * |Stirling1(n,k)|.
a(n) ~ sqrt(Pi/2) * n^(n + 7/2) / (3 * (exp(1) - 1)^(n+4)). - Vaclav Kotesovec, Jun 04 2022
a(0) = 1; a(n) = Sum_{k=1..n} (3*k/n + 1) * (k-1)! * binomial(n,k) * a(n-k). - Seiichi Manyama, Nov 19 2023
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+log(1-x))^4))
(PARI) a(n) = sum(k=0, n, (k+3)!*abs(stirling(n, k, 1)))/6;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 17 2022
STATUS
approved