A124463 Row 3 of rectangular table A124460.

1, 4, 13, 44, 162, 637, 2622, 11188, 49293, 223768, 1044661, 5006126, 24580704, 123464593, 633467893, 3315948760, 17690431736, 96101620364, 531196784996, 2985589206506, 17053375055317, 98942675518256, 582858713958087

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Formula

G.f.: A(x) = Sum_{n>=0} x^n*R_n(x)^3, where R_n(x) is the g.f. of row n in table A124460 and satisfies: R_n(x) = Sum_{k>=0} x^k * R_k(x)^n for n>=0.

Prog

(PARI) {a(n)=local(m=max(n, 3), R=vector(m+1, r, vector(m+1, c, binomial(r+c-2, c-1)))); for(i=0, m, for(r=0, m, R[r+1]=Vec(sum(c=0, m, x^c*Ser(R[c+1])^r+O(x^(m+1)))))); R[4][n+1]}

Crossrefs

Cf. A124460 (table); other rows: A124461, A124462, A124464, A124465, A124466.

Sequence in context: A149429 A045652 A149430 * A081197 A005490 A174299

Adjacent sequences: A124460 A124461 A124462 * A124464 A124465 A124466

Keyword

nonn

Author

Paul D. Hanna, Nov 03 2006

Status

approved