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 A129103 #5 Jun 14 2017 00:27:54 %S A129103 1,8,72,880,16032,461992,21944520,1770483408,248136807776, %T A129103 61460157645704,27267123945408968,21902527945097597616, %U A129103 32134030755805852610720,86739696410985770930422760 %N A129103 Column 3 of triangle A129100; also equals column 0 of matrix power A129100^8. %o A129103 (PARI) a(n)=local(A=Mat(1),B);for(m=1,n+4,B=matrix(m,m);for(r=1,m,for(c=1,r, if(r==c || r==1 || r==2,B[r,c]=1,if(c==1,B[r,1]=sum(i=1,r-1,A[r-1,i]), B[r,c]=(A^(2^(c-1)))[r-c+1,1])); )); A=B); return(A[n+4,4]) %Y A129103 Cf. A129100 (triangle); A129092 (column 0), A129101 (column 1), A129102 (column 2). %K A129103 nonn %O A129103 0,2 %A A129103 _Paul D. Hanna_, Mar 29 2007