OFFSET
0,3
COMMENTS
Conjectured to consist entirely of integers.
EXAMPLE
G.f.: A(x) = 1 + x + 2*x^2 + 18*x^3 + 476*x^4 + 38358*x^5 +...
...
A(x) = 1 + x*exp( [A(2x)-1] + [A(4x)-1]^2/2 + [A(8x)-1]^3/3 +... ).
PROG
(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=1, n, A=1+x*exp(sum(k=1, n, (subst(A, x, 2^k*x+x*O(x^n))-1)^k/k))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 04 2009
STATUS
approved