A122891 Column sums of triangle A122890.

1, 1, 3, 28, 1625, 3247268, 10649997137454, 113423713055030979289411081, 12864938683278671740537137672878980378983810317967737

Offset

0,3

Links

Table of n, a(n) for n=0..8.

Prog

(PARI) {A122890(n, k)=local(F=x+x^2, G=x+x*O(x^k)); if(n<0, 0, for(i=1, n, G=subst(F, x, G)); polcoeff(G, k, x))}
/* Takes first 2^m terms in column m of A122890 to compute a(m): */
{for(m=0, 8, print1(polcoeff(sum(N=1, 2^m, sum(n=0, 2^m, A122890(n, N)*x^n)*(1-x)^N+O(x^12)), m), ", "))}

Crossrefs

Cf. A122890, A122888; A007018.

Sequence in context: A140990 A196735 A208438 * A119156 A175979 A096621

Adjacent sequences: A122888 A122889 A122890 * A122892 A122893 A122894

Keyword

nonn

Author

Paul D. Hanna, Sep 18 2006

Status

approved