A112914 Column 3 of triangle A112911.

1, 4, 24, 176, 1492, 14220, 149812, 1724760, 21519108, 289101836, 4160750192, 63873461064, 1042061108096, 18008563271632, 328712410879632, 6320649807989400, 127724091041379492, 2706397280528315148

Offset: 0

Author

Paul D. Hanna, Oct 06 2005

Keywords

• nonn

Crossrefs

Cf. A112911 (triangle), A088716 (column 0), A112912 (column 1), A112913 (column 2).

Programs

PARI

{a(n)=local(A=Mat(1),B);for(m=2,n+4,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+4,4])}

Formula

a(n) = Sum_{k=0..n-1} (n-k+3)*A088716(k)*a(n-k-1) for n>0 with a(0)=1.