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 A162998 #4 Jun 02 2025 01:46:54 %S A162998 1,3,9,29,100,369,1458,6160,27740 %N A162998 Row sums of triangle A162997. %e A162998 a(4) = 29 = (1 + 13 + 11 + 4) = sum of row 3 terms, triangle A162997 %Y A162998 A162997 %K A162998 nonn %O A162998 0,2 %A A162998 _Gary W. Adamson_, Jul 23 2009