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 A134840 #6 Mar 27 2022 18:35:55 %S A134840 1,1,2,1,3,3,1,2,3,4,1,3,4,6,5,1,2,3,4,5,6,1,3,3,7,5,9,7,1,2,4,4,5,8, %T A134840 7,8,1,3,3,6,6,9,7,12,9,1,2,3,4,5,6,7,8,9,10,1,3,4,7,5,12,7,14,12,15, %U A134840 11 %N A134840 Triangle, antidiagonals of an array formed by A051731 * A126988(transform). %C A134840 Row sums = A069153: (1, 3, 7, 10, 19, 21, 35, 39, ...). %F A134840 Triangle, antidiagonals of an array formed by A051731 * A126988(transform). %e A134840 First few rows of the array: %e A134840 1, 2, 3, 4, 5, 6, 7, ... %e A134840 1, 3, 3, 6, 5, 9, 7, ... %e A134840 1, 2, 4, 4, 5, 8, 7, ... %e A134840 1, 3, 3, 7, 5, 9, 7, ... %e A134840 1, 2, 3, 4, 6, 6, 7, ... %e A134840 ... %e A134840 First few rows of the triangle: %e A134840 1; %e A134840 1, 2; %e A134840 1, 3, 3; %e A134840 1, 2, 3, 4; %e A134840 1, 3, 4, 6, 5; %e A134840 1, 2, 3, 4, 5, 6; %e A134840 1, 2, 3, 7, 5, 9, 7; %e A134840 1, 2, 4, 4, 5, 8, 7, 8; %e A134840 ... %Y A134840 Cf. A051731, A126988, A069153. %K A134840 nonn,tabl %O A134840 1,3 %A A134840 _Gary W. Adamson_, Nov 12 2007