A121414 Column 2 of triangle A121412, in which row n of T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

1, 1, 5, 45, 581, 9730, 199692, 4843125, 135345925, 4278317373, 150818840250, 5863215069621, 249105031449435, 11480173020040450, 570303168053225908, 30375972794764190385, 1726700205634807475115, 104332294453480284687895

Offset

0,3

Comments

Also equals column 4 of triangle A101479.

Links

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

Prog

(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^1)[n+3, 3])}

Crossrefs

Cf. A121412 (triangle); other columns: A101483, A121413, A121415; A101479 (triangle).

Sequence in context: A375952 A375951 A174495 * A243678 A097328 A051539

Adjacent sequences: A121411 A121412 A121413 * A121415 A121416 A121417

Keyword

nonn

Author

Paul D. Hanna, Aug 22 2006

Status

approved