cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A107674 Matrix square of triangle A107671.

Original entry on oeis.org

1, 24, 4, 2268, 135, 9, 461056, 15936, 448, 16, 160977375, 3789250, 69000, 1125, 25, 85624508376, 1485395280, 19994688, 223560, 2376, 36, 64363893844726, 862907827866, 9138674195, 79086196, 596820, 4459, 49, 64928246784463872
Offset: 0

Views

Author

Paul D. Hanna, Jun 07 2005

Keywords

Comments

Column 0 is A107675.

Examples

			Triangle T(n,k) (with rows n >= 0 and columns k = 0..n) begins:
            1;
           24,          4;
         2268,        135,        9;
       461056,      15936,      448,     16;
    160977375,    3789250,    69000,   1125,   25;
  85624508376, 1485395280, 19994688, 223560, 2376, 36;
  ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(P=matrix(n+1,n+1,r,c,if(r>=c,(r^3)^(r-c)/(r-c)!)), D=matrix(n+1,n+1,r,c,if(r==c,r)));if(n>=k,(P^-1*D^2*P)[n+1,k+1])}

Formula

Matrix diagonalization method: define the triangular matrix P by P(n, k) = ((n+1)^3)^(n-k)/(n-k)! for n >= k >= 0 and the diagonal matrix D by D(n, n) = n+1 for n >= 0; then T is given by T = P^-1*D^2*P.