A124467 Main diagonal of rectangular table A124460.

1, 2, 8, 44, 302, 2437, 22143, 220663, 2377322, 27462836, 338270681, 4422338285, 61114545578, 889542935517, 13593252066134, 217461100417945, 3632859088845390, 63233532604594586, 1144455373221119025

Offset

0,2

Comments

In table A124460, the g.f. of row n, R_n(y), simultaneously satisfies: R_n(y) = Sum_{k>=0} y^k * R_k(y)^n for n>=0.

Links

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

Prog

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

Crossrefs

Cf. A124460 (table); rows: A124461, A124462, A124463, A124464, A124465, A124466; A124468 (diagonal).

Sequence in context: A112912 A303613 A321942 * A075792 A052897 A137984

Adjacent sequences: A124464 A124465 A124466 * A124468 A124469 A124470

Keyword

nonn

Author

Paul D. Hanna, Nov 03 2006

Status

approved