A178089 G.f. satisfies: A(x) = Sum_{n>=0} x^n * Product_{k=0..n-1} A(2^k*x).

1, 1, 2, 6, 26, 164, 1548, 22612, 527016, 20075480, 1272488296, 136039530768, 24791209794352, 7767414503113808, 4214117431305739680, 3983248890848252043616, 6594358097712974323610528, 19210839739434953100591639104, 98895926239537023373263092515008

Offset

0,3

Links

Table of n, a(n) for n=0..18.

Example

G.f.: A(x) = 1 + x + 2*x^2 + 6*x^3 + 26*x^4 + 164*x^5 +...
where
A(x) = 1 + x*A(x) + x^2*A(x)*A(2*x) + x^3*A(x)*A(2*x)*A(4*x) +...

Prog

(PARI) {a(n, r=1)=local(A=1+x); for(i=1, n, A=1+sum(m=1, n, r^m*x^m*prod(k=0, m-1, subst(A, x, 2^k*x+x*O(x^n))))); polcoeff(A, n)}
for(n=0, 20, print1(a(n), ", "))

Crossrefs

Cf. A230316, A158888.

Sequence in context: A141713 A005272 A307082 * A363003 A002449 A059430

Adjacent sequences: A178086 A178087 A178088 * A178090 A178091 A178092

Keyword

nonn

Author

Paul D. Hanna, May 19 2010

Status

approved