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

Author

Paul D. Hanna, Aug 26 2006

Keywords

• nonn

Comments

Also main diagonal of square array A136733.

Crossrefs

Cf. A121424, A121412.

Cf. A136733; A101483, A121418, A121421.

Programs

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])}

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).

Extensions

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