A121429 Main diagonal of rectangular table A121428.

1, 2, 18, 250, 4520, 99351, 2556806, 75190410, 2483617140, 90955908010, 3655774038653, 159938142409890, 7564604603286913, 384576889110665055, 20912407157570989950, 1211142337261176799610, 74427504634177621877538

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Formula

a(n) = [A121412^(n+1)](n+2,2) for n>=0; i.e., the (n+1)-th term of column 2 in matrix power A121412^(n+1).

Prog

(PARI) {a(n)=local(H=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]=(H^i)[i-1, j]); )); H=B); return((H^(n+1))[n+3, 3])}

Crossrefs

Cf. A121428, A121412.

Sequence in context: A117514 A138437 A265452 * A368466 A337775 A276364

Adjacent sequences: A121426 A121427 A121428 * A121430 A121431 A121432

Keyword

nonn

Author

Paul D. Hanna, Aug 26 2006

Status

approved