OFFSET
0,3
COMMENTS
a(n) = n! * A004111(n).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..150
FORMULA
E.g.f. A(x) satisfies A(x) = x Product_{n>=1} x*(1 + x^n)^(a(n)/n!).
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(binomial(b(i-1$2), j)*b(n-i*j, i-1), j=0..n/i)))
end:
a:= n-> n!*b(n-1$2):
seq(a(n), n=0..25); # Alois P. Heinz, Aug 14 2013
MATHEMATICA
nn=20; SolveAlways[
0 == Series[
f[x] - x Product[(1 + x^i)^(a[i]/i!), {i, 1, nn}], {x, 0, nn}],
x]; Table[a[n], {n, 0, nn}] /. sol
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, Aug 14 2013
STATUS
approved