OFFSET
0,3
EXAMPLE
G.f.: A(x) = 1 + x + 6*x^2 + 48*x^3 + 977*x^4 + 13378*x^5 +...
The g.f. A = A(x) satisfies:
log(A) = x*A + x^2*(A + 2*A^2)^2/2 + x^3*(A + 3*A^3)^3/3 + x^4*(A + 2*A^2 + 4*A^4)^4/4 + x^5*(A + 5*A^5)^5/5 + x^6*(A + 2*A^2 + 3*A^3 + 6*A^6)^6/6 +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, (x^m/m)*sumdiv(m, d, d*A^d)^m+x*O(x^n)))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 09 2011
STATUS
approved