A156907 G.f.: A(x) = 1 + x*exp( Sum_{k>=1} [A(2^k*x) - 1]^k/k ).

1, 1, 2, 18, 476, 38358, 11363548, 15060027956, 92500603618872, 2483766272252845670, 279689176516909339664044, 129570236404446129260308225372, 244562582019257683819447274838128648

Offset

0,3

Comments

Conjectured to consist entirely of integers.

Links

Table of n, a(n) for n=0..12.

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

Cf. A156908.

Sequence in context: A082402 A208055 A306655 * A053916 A355131 A355134

Adjacent sequences: A156904 A156905 A156906 * A156908 A156909 A156910

Keyword

nonn

Author

Paul D. Hanna, Mar 04 2009

Status

approved