A113992 Column 3 of triangle A113988, which is the matrix square of A113983: a(n) = [A113983^2](n+3,3).

1, 8, 46, 248, 1366, 7976, 50186, 342584, 2541682, 20478832, 178809686, 1687157648, 17149281446, 187185819536, 2187084736978, 27270946449584, 361839376952194, 5094730546999608, 75927073509816766, 1194793354659948104

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Prog

(PARI) a(n)=local(A, B); A=Mat(1); for(m=2, n+4, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 || j==1 || j==i, B[i, j]=1, B[i, j]=A[i-1, j-1]+(A^2)[i-2, j-1] ); )); A=B); (A^2)[n+4, 4]

Crossrefs

Cf. A113988, A113989 (column 0), A113990 (column 1), A113991 (column 2).

Sequence in context: A026885 A052244 A083421 * A352094 A037070 A141788

Adjacent sequences: A113989 A113990 A113991 * A113993 A113994 A113995

Keyword

nonn

Author

Paul D. Hanna, Nov 12 2005

Status

approved