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 A113348 #5 Jun 13 2017 22:51:39 %S A113348 1,10,105,1315,19875,357860,7547602,183518246,5072961513,157525315615, %T A113348 5438681986872,206954207984234,8613936431369952,389602050945939891, %U A113348 19038814387466399303,1000152089409979423044,56229083214210734799693 %N A113348 Column 2 of triangle A113345, also equals column 0 of A113350^5. %C A113348 A113345 is the matrix square of A113340. %o A113348 (PARI) a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+3,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+3,3] %Y A113348 Cf. A113340, A113345, A113346 (column 0), A113347 (column 1), A113349 (column 3); A113350. %K A113348 nonn %O A113348 0,2 %A A113348 _Paul D. Hanna_, Nov 08 2005