A127783 G.f. satisfies: A(x) = 1 + x*A(x+x^2)^2.

1, 1, 2, 7, 28, 133, 700, 4039, 25160, 167637, 1186482, 8872752, 69810994, 575912978, 4967058182, 44675926159, 418157494016, 4065044047125, 40973402647058, 427535487044903, 4611642948647118, 51354908876927025

Offset

0,3

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..310

Prog

(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1+x*subst(A^2, x, x+x^2)); polcoeff(A, n)}

Crossrefs

Cf. A127782, A127784.

Sequence in context: A252737 A217203 A052319 * A297195 A116539 A266467

Adjacent sequences: A127780 A127781 A127782 * A127784 A127785 A127786

Keyword

nonn

Author

Paul D. Hanna, Jan 28 2007

Status

approved