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 A129801 #7 Sep 24 2018 16:53:14 %S A129801 1,1,3,1,5,9,1,7,13,19,1,9,17,25,33,1,11,21,31,41,51,1,13,25,37,49,61, %T A129801 73,1,15,29,43,57,71,85,99,1,17,33,49,65,81,97,113,129,1,19,37,55,73, %U A129801 91,109,127,145,163,1,21,41,61,81,101,121,141,161,181,201 %N A129801 Triangle read by rows in which row m (m>=0) gives the numbers 2*m*n + 1 for n = 0, ..., m. %C A129801 Row sums are given by A053698 = n^3 + n^2 + n + 1. %e A129801 1; 1,3; 1,5,9; 1,7,13,19; 1,9,17,25,33; ... %Y A129801 Cf. A053698. %K A129801 nonn,tabl %O A129801 1,3 %A A129801 _Roger L. Bagula_, May 18 2007 %E A129801 Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, May 20 2007