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 A135152 #5 Mar 27 2022 18:27:10 %S A135152 1,2,1,4,2,1,4,4,2,1,6,4,4,2,1,6,6,4,4,2,1,8,6,6,4,4,2,1,8,8,6,6,4,4, %T A135152 2,1,10,8,8,6,6,4,4,2,1,10,10,8,8,6,6,4,4,2,1 %N A135152 A004736 + A128174 - I, I = Identity matrix. %C A135152 Row sums = A047838: (1, 3, 7, 11, 17, 23, 31, 39, ...). The triangle is a companion to A135151. %F A135152 A004736 + A128174 - I, where I = Identity matrix, A004736 = (1; 2,1; 3,2,1; ...) and A128174 = (1; 0,1; 1,0,1; 0,1,0,1; ...). %e A135152 First few rows of the triangle: %e A135152 1; %e A135152 2, 1; %e A135152 4, 2, 1; %e A135152 4, 4, 2, 1; %e A135152 6, 4, 4, 2, 1; %e A135152 6, 6, 4, 4, 2, 1; %e A135152 8, 6, 6, 4, 4, 2, 1; %e A135152 ... %Y A135152 Cf. A135151, A047838, A004736, A128174. %K A135152 nonn,tabl %O A135152 1,2 %A A135152 _Gary W. Adamson_, Nov 21 2007