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 A128142 #7 Feb 15 2022 11:12:34 %S A128142 1,5,2,15,8,3,34,21,11,4,65,44,27,14,5,111,80,54,33,17,6,175,132,95, %T A128142 64,39,20,7,260,203,153,110,74,45,23,8,369,296,231,174,125,84,51,26,9, %U A128142 505,414,332,259,195,140,94,57,29,10 %N A128142 A128132 * A122432 (unsigned). %C A128142 Row sums = A006325 starting (1, 7, 26, 70, 155, ...). %C A128142 Left border = A006003: (1, 5, 15, 34, 65, 111, ...). %C A128142 A128141 = A122432 * A128132. %F A128142 A128132 * A122432 (unsigned); as infinite lower triangular matrices. %e A128142 First few rows of the triangle: %e A128142 1; %e A128142 5, 2; %e A128142 15, 8, 3; %e A128142 34, 21, 11, 4; %e A128142 65, 44, 27, 14, 5; %e A128142 111, 80, 54, 33, 17, 6; %e A128142 175, 132, 95, 64, 39, 20, 7; %e A128142 ... %Y A128142 Cf. A128132, A122432, A006325, A128141, A006003. %K A128142 nonn,tabl %O A128142 1,2 %A A128142 _Gary W. Adamson_, Feb 16 2007