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 A113343 #5 Jun 13 2017 22:50:32 %S A113343 1,7,70,889,13853,258146,5633264,141487178,4031806898,128792484219, %T A113343 4565493788191,178051324792642,7583098790779316,350435514388561567, %U A113343 17474323210108996497,935597107908721785211,53553176933223851350863 %N A113343 Column 3 of triangle A113340, also equals column 0 of A113340^7. %o A113343 (PARI) a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+4,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(2*j-1))[i-j+1,1]));));A=B);A[n+4,4] %Y A113343 Cf. A113341 (column 1), A113342 (column 2), A113344 (column 4), A113340. %K A113343 nonn %O A113343 0,2 %A A113343 _Paul D. Hanna_, Nov 08 2005