A121425 Main diagonal of rectangular table A121424.

1, 2, 12, 118, 1605, 27816, 585046, 14459138, 410368743, 13146830110, 469123986529, 18447791712945, 792514583941223, 36925394368325295, 1854525584914459755, 99872579714406393286, 5740977285851988017769

Offset

0,2

Comments

Also main diagonal of square array A136733.

Links

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

Formula

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

Prog

(PARI) {a(n)=local(H=Mat(1), B); for(m=1, n+1, 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+1, 1])}

Crossrefs

Cf. A121424, A121412.

Cf. A136733; A101483, A121418, A121421.

Sequence in context: A012623 A009742 A279201 * A132692 A377692 A009546

Adjacent sequences: A121422 A121423 A121424 * A121426 A121427 A121428

Keyword

nonn

Author

Paul D. Hanna, Aug 26 2006

Extensions

Edited by N. J. A. Sloane, Oct 30 2008 at the suggestion of R. J. Mathar

Status

approved