OFFSET
0,3
LINKS
Eric Weisstein's World of Mathematics, Lambert W-Function.
FORMULA
a(n) = n! * [x^n] exp(-x) / (1 + LambertW(-n*x)).
a(n) = [x^n] Sum_{k>=0} (n*k*x)^k / (1 + x)^(k+1).
PROG
(PARI) a(n) = (-1)^n * sum(k=0, n, (-n*k)^k*binomial(n, k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 06 2023
STATUS
approved