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 A047868 #7 Mar 30 2012 18:38:43 %S A047868 1,22,328,4400,58140,785256 %N A047868 Erroneous version of A002539. %C A047868 More generally the main diagonal of the array defined by T(0,j)=j+1 j>=0, T(i,0)=i+1 i>=0, T(i,j)=T(i-1,j-1)+T(i-1,j)+ A, is given by T(n,n)=2^(n-1)*(n+2A+2)-A - _Benoit Cloitre_, Jun 17 2003 %F A047868 Main diagonal of the array defined by T(0, j)=j+1 j>=0, T(i, 0)=i+1 i>=0, T(i, j)=T(i-1, j-1)+T(i-1, j)+ 6; a(n)=2^(n-1)*(n+14)-6 - _Benoit Cloitre_, Jun 17 2003 %K A047868 dead %O A047868 1,2