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 A131375 #2 Mar 30 2012 17:25:22 %S A131375 1,2,1,1,3,1,2,3,4,1,1,6,6,5,1,2,5,13,10,6,1,1,9,15,24,15,7,1,2,7,27, %T A131375 35,40,21,8,1,1,12,28,66,70,62,28,9,1,2,9,46,84,141,126,91,36,10,1 %N A131375 A007318 + A046854 - A049310. %C A131375 Row sums = A117591: (1, 3, 5, 10, 19, 37, 72,...). %F A131375 A007318 + A046854 - A049310 as infinite lower triangular matrices. %e A131375 First few rows of the triangle are: %e A131375 1; %e A131375 2, 1; %e A131375 1, 3, 1; %e A131375 2, 3, 4, 1; %e A131375 1, 6, 6, 5, 1; %e A131375 2, 5, 13, 10, 6, 1; %e A131375 1, 9, 15, 24, 15, 7, 1; %e A131375 ... %Y A131375 Cf. A046854, A007318, A049310, A117591. %K A131375 nonn,tabl %O A131375 0,2 %A A131375 _Gary W. Adamson_, Jul 04 2007