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 A125798 #5 Jun 14 2017 00:16:22 %S A125798 1,4,35,656,25509,2026564,326603719,106355219008,69808185542089, %T A125798 92203545302072964,244779396712068825067,1305009502037405316440848, %U A125798 13963029918525356899170492525,299675759834305402824238609624548 %N A125798 A diagonal of table A125790: a(n) = A125790(n+1,n). %o A125798 (PARI) a(n)=local(q=2,A=Mat(1), B); for(m=1, n+2, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i || j==1, B[i, j]=1, B[i, j]=(A^q)[i-1, j-1]); )); A=B); return(sum(c=0,n+1,(A^n)[n+2,c+1])) %Y A125798 Cf. A125790, A078121; columns: A002577, A125792, A125793, A125794, A125795, A125796; A125797 (diagonal). %K A125798 nonn %O A125798 0,2 %A A125798 _Paul D. Hanna_, Dec 10 2006