OFFSET
0,3
EXAMPLE
G.f.: A(x) = 1 + x + 3*x^2 + 15*x^3 + 145*x^4 + 2489*x^5 +...
The logarithm of the g.f. equals the series:
log(A(x)) = A(2*x)*x + A(2^4*x^2)*x^2/2 + A(2^9*x^3)*x^3/3 + A(2^16*x^4)*x^4/4 +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, subst(A, x, 2^(m^2)*x^m+x*O(x^n))*x^m/m))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 30 2010
STATUS
approved