A121419 Column 2 of triangle A121416.

1, 2, 11, 101, 1305, 21745, 443329, 10679494, 296547736, 9319259500, 326788327650, 12643827604842, 534889691765631, 24555735428777265, 1215611513578215355, 64542477563559758310, 3658333757447085090365

Offset: 0

Author

Paul D. Hanna, Aug 22 2006

Keywords

• nonn

Comments

A121416 is the matrix square of triangle A121412; row n of triangle T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

Crossrefs

Cf. A121416 (triangle); other columns: A121417, A121418.

Programs

PARI

{a(n)=local(A=Mat(1), B); for(m=1, n+3, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i,j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^2)[n+3, 3])}