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 A113347 #5 Jun 13 2017 22:50:25 %S A113347 1,6,39,327,3556,48659,812462,16136404,373415239,9900007028, %T A113347 296557405704,9921937128500,367181525916035,14906571298831661, %U A113347 659191947156441025,31558799717042019635,1626968083690674214906 %N A113347 Column 1 of triangle A113345, also equals column 0 of A113350^3. %C A113347 A113345 is the matrix square of A113340. %o A113347 (PARI) a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+2,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^2)[n+2,2] %Y A113347 Cf. A113340, A113345, A113346 (column 0), A113348 (column 2), A113349 (column 3); A113350. %K A113347 nonn %O A113347 0,2 %A A113347 _Paul D. Hanna_, Nov 08 2005