OFFSET
0,2
LINKS
Eric Weisstein's World of Mathematics, Lambert W-Function.
FORMULA
E.g.f.: 1/(1 + LambertW( 2 * log(1+x) )), where LambertW() is the Lambert W-function.
a(n) ~ (-1)^n * exp(-1/2 - n + n*exp(-1)/2) * n^n / (sqrt(2) * (exp(exp(-1)/2) - 1)^(n+1/2)). - Vaclav Kotesovec, Feb 06 2022
PROG
(PARI) a(n) = sum(k=0, n, (-2*k)^k*stirling(n, k, 1));
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(1+lambertw(2*log(1+x)))))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Feb 05 2022
STATUS
approved