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.
%I A102104 #4 Mar 30 2012 18:36:44
%S A102104 1,3,34,2125,399551,167436757,133589812359,182634217743739,
%T A102104 396471609861950572,1290175805332297239092,6016194958934722148801658,
%U A102104 38771533093655782191893463830,335219158226849230801472869515158
%N A102104 Row sums of triangular matrix A102101, which shifts upward to exclude the main diagonal under matrix fourth power.
%o A102104 (PARI) {a(n)=local(A=matrix(2,2),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^4)[i-1,1], B[i,j]=(A^4)[i-1,j]));));A=B); return(sum(k=0,n,A[n+1,k+1]))}
%Y A102104 Cf. A102101.
%K A102104 nonn
%O A102104 0,2
%A A102104 _Paul D. Hanna_, Dec 29 2004