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 A131953 #5 Mar 05 2022 01:01:43 %S A131953 1,4,2,4,5,4,10,5,7,8,16,11,7,11,16,34,17,13,11,19,32,64,35,19,17,19, %T A131953 35,64,130,65,37,23,25,35,67,128,256,131,67,41,31,41,67,131,256,514, %U A131953 257,133,71,49,47,73,131,259,512 %N A131953 A130321 + A059268 - A000012(signed). %C A131953 Row sums = A101622 starting (1, 6, 13, 30, 61, 126, ...). %F A131953 A130321 + A059268 - A000012 (signed + - + -, ... by columns) as infinite lower triangular matrices. %e A131953 First few rows of the triangle: %e A131953 1; %e A131953 4, 2; %e A131953 4, 5, 4; %e A131953 10, 5, 7, 8; %e A131953 16, 11, 7, 11, 16; %e A131953 34, 17, 13, 11, 19, 32; %e A131953 64, 35, 19, 17, 19, 35, 64; %e A131953 ... %Y A131953 Cf. A130321, A059268, A101622. %K A131953 nonn,tabl %O A131953 0,2 %A A131953 _Gary W. Adamson_, Jul 30 2007