A127785 G.f. satisfies: A(x) = 1 + x*A(x+x^2)^3.

1, 1, 3, 15, 88, 594, 4404, 35260, 300918, 2714187, 25715364, 254752536, 2629587927, 28202629918, 313575278100, 3607684547463, 42880301468830, 525812475574788, 6643855672178904, 86407881067891029, 1155583581407910414

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Prog

(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1+x*subst(A^3, x, x+x^2)); polcoeff(A, n)}

Crossrefs

Cf. A127782, A127783.

Sequence in context: A368972 A370472 A365128 * A287511 A231257 A074541

Adjacent sequences: A127782 A127783 A127784 * A127786 A127787 A127788

Keyword

nonn

Author

Paul D. Hanna, Jan 28 2007

Status

approved