OFFSET
0,2
FORMULA
a(n) = n! * Sum_{k=0..n} 2^k * |Stirling1(n,k)|/(n-k+1)!.
E.g.f. A(x) satisfies: A(x) = 1 - 2*log(1 - x*A(x)). - Ilya Gutkovskiy, Jun 10 2026
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x/(1-2*log(1-x)))/x))
(PARI) a(n) = n!*sum(k=0, n, 2^k*abs(stirling(n, k, 1))/(n-k+1)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 07 2024
STATUS
approved
