OFFSET
0,4
LINKS
Eric Weisstein's World of Mathematics, Lambert W-Function.
FORMULA
E.g.f.: exp(x - LambertW(2*x^2 * exp(2*x))/2) = sqrt( LambertW(2*x^2 * exp(2*x))/(2*x^2) ).
a(n) = n! * Sum_{k=0..floor(n/2)} (-1)^k * (2*k+1)^(n-k-1) / (k! * (n-2*k)!).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x-lambertw(2*x^2*exp(2*x))/2)))
CROSSREFS
KEYWORD
sign,changed
AUTHOR
Seiichi Manyama, Apr 21 2023
STATUS
approved