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 A141156 #2 Mar 30 2012 17:25:28 %S A141156 1,3,9,21,46,88,165,285,483,783,1245,1917,2918,4332 %N A141156 Row sums of triangle A141155. %e A141156 a(3) = 21 since row 3 of triangle A141155 = (7, 6, 5, 3). 21 = (7 + 6 + 5 + 3). %Y A141156 Cf. A141155. %K A141156 nonn %O A141156 0,2 %A A141156 _Gary W. Adamson_, Jun 12 2008