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 A128971 #4 Feb 18 2022 22:26:56 %S A128971 1,2,2,5,4,4,10,10,8,8,21,20,20,16,16,42,42,40,40,32,32,85,84,84,80, %T A128971 80,64,64,170,170,168,168,160,160,128 %N A128971 A130125 * A000012. %C A128971 Left column = A000975: (1, 2, 5, 10, 21, 42, ...). Row sums = A102301: (1, 4, 13, 36, 93, ...). A130127 = A000012 * A130125. %F A128971 A130125 * A000012 as infinite lower triangular matrices. %e A128971 First few rows of the triangle: %e A128971 1; %e A128971 2, 2; %e A128971 5, 4, 4; %e A128971 10, 10, 8, 8; %e A128971 21, 20, 20, 16, 16; %e A128971 42, 42, 40, 40, 32, 32; %e A128971 85, 84, 84, 80, 80, 64, 64; %e A128971 ... %Y A128971 Cf. A000975, A102301, A130127, A000012, A130125. %K A128971 nonn,tabl %O A128971 0,2 %A A128971 _Gary W. Adamson_, May 11 2007