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 A131900 #6 Mar 05 2022 01:47:46
%S A131900 1,1,2,3,0,3,3,1,0,4,5,0,1,0,5,5,1,0,1,0,6,7,0,1,0,1,0,7,7,1,0,1,0,1,
%T A131900 0,8,9,0,1,0,1,0,1,0,9,9,1,0,1,0,1,0,1,0,10
%N A131900 A131821 + A128174 - A000012.
%C A131900 Row sums = A047219, numbers congruent to {1, 3} (mod 5): (1, 3, 6, 8, 11, 13, ...).
%F A131900 A131821 + A128174 - A000012 as infinite lower triangular matrices.
%e A131900 First few rows of the triangle:
%e A131900 1;
%e A131900 1, 2;
%e A131900 3, 0, 3;
%e A131900 3, 1, 0, 4;
%e A131900 5, 0, 1, 0, 5;
%e A131900 5, 1, 0, 1, 0, 6;
%e A131900 7, 0, 1, 0, 1, 0, 7;
%e A131900 ...
%Y A131900 Cf. A131821, A128174, A047219.
%K A131900 nonn,tabl
%O A131900 0,3
%A A131900 _Gary W. Adamson_, Jul 25 2007