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.

A111847 Row sums of triangle A111845, which shifts columns left and up under matrix 4th power.

Original entry on oeis.org

1, 2, 9, 97, 2689, 214017, 53130241, 43283609601, 119521939222529, 1144341237628100609, 38638551719263573098497, 4662529388979590206324834305, 2032489532637330252763496597356545
Offset: 0

Views

Author

Paul D. Hanna, Aug 23 2005

Keywords

Crossrefs

Cf. A111845 (triangle), A078537 (variant).

Programs

  • PARI
    {a(n,q=4)=local(A=Mat(1),B);if(n<0,0, for(m=1,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=1,if(j==1,B[i,j]=(A^q)[i-1,1], B[i,j]=(A^q)[i-1,j-1]));));A=B); return(sum(k=0,n,A[n+1,k+1])))}