OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..150
FORMULA
a(n) = n! * [x^n] exp(Sum_{d|(n-1)} (x*exp(x))^d/d) for n>1, a(0)=a(1)=1.
a(n) = A245501(n,n).
MAPLE
with(numtheory):
a:= n-> `if`(n<2, 1, n! *coeff(series(
exp(add((x*exp(x))^d/d, d=divisors(n-1))), x, n+1), x, n)):
seq(a(n), n=0..25);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 24 2014
STATUS
approved