OFFSET
0,4
FORMULA
a(n) = Sum_{k=0..n} 3^(n-k) * Stirling1(n,k) * Bell(k).
a(n) = (1/e) * 3^n * n! * Sum_{k>=0} binomial(k/3,n)/k!.
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp((1+3*x)^(1/3)-1)))
CROSSREFS
KEYWORD
sign,new
AUTHOR
Seiichi Manyama, Jan 16 2025
STATUS
approved