OFFSET
0,3
FORMULA
a(n) = n! * Sum_{k=0..n} 3^(n-k) * |Stirling1(n,k)|/(n-k+1)!.
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x/(1-log(1-3*x)/3))/x))
(PARI) a(n) = n!*sum(k=0, n, 3^(n-k)*abs(stirling(n, k, 1))/(n-k+1)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 08 2024
STATUS
approved