A166909 Row sums of triangle A166905.

1, 2, 11, 97, 1145, 16796, 293623, 5950792, 137075837, 3535416136, 100902444181, 3156570232069, 107392381479683, 3947409366073512, 155880018189733841, 6581149438442041483, 295807451972657856921, 14102499966460374953016

Offset

0,2

Comments

Triangle A166905 transforms rows into diagonals in the table A158825 of coefficients in successive iterations of x*Catalan(x) (cf. A000108).

Links

Table of n, a(n) for n=0..17.

Prog

(PARI) {a(n)=local(F=x, G=serreverse(x-x^2+O(x^(n+3))), M, N, P, m=n); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, G+x*O(x^(m+3)))); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, F=x; for(i=1, r, F=subst(F, x, G+x*O(x^(m+3)))); polcoeff(F, c)); P=matrix(n+1, n+1, r, c, M[r+1, c]); M=(P~*N~^-1); sum(k=1, n+1, M[n+1, k])}

Crossrefs

Cf. A166905, A158831, A166906, A166907, A166908.

Sequence in context: A055680 A260957 A368292 * A362467 A020559 A230889

Adjacent sequences: A166906 A166907 A166908 * A166910 A166911 A166912

Keyword

nonn

Author

Paul D. Hanna, Nov 28 2009

Status

approved