OFFSET
0,4
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..210
FORMULA
G.f.: A(x) = 1 + x * Product_{k>=1} A(x^k).
a(n) ~ c * d^n, where d = 1.93144101206639993844275031844664... and c = 0.29686384114142059645291926346897... - Vaclav Kotesovec, Oct 02 2020
PROG
(PARI) {a(n)=local(A); A=1+x; for(i=1, n, A=1+x*prod(k=1, n, subst(A, x, x^k))+x*O(x^n)); polcoeff(A, n, x)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Feb 05 2004
STATUS
approved