A112912 Column 1 of triangle A112911.

1, 2, 8, 44, 298, 2358, 21154, 211100, 2313030, 27566654, 354806116, 4903884712, 72444584732, 1139381007880, 19012236634968, 335560664081388, 6247230709277958, 122375974186267566, 2516528486416495240

Offset

0,2

Links

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

Formula

a(n) = Sum_{k=0..n-1} (n-k+1)*A088716(k)*a(n-k-1) for n>0 with a(0)=1.

Prog

(PARI) {a(n)=local(A=Mat(1), B); for(m=2, n+2, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=-j*(A^-1)[i-j, 1]); )); A=B); return((A^-1)[n+2, 2])}

Crossrefs

Cf. A088716, A112911.

Sequence in context: A318977 A111537 A051045 * A303613 A321942 A124467

Adjacent sequences: A112909 A112910 A112911 * A112913 A112914 A112915

Keyword

nonn

Author

Paul D. Hanna, Oct 06 2005

Status

approved