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 A202698 #11 Oct 20 2014 17:15:13 %S A202698 0,0,0,3,3,3,0,3,6,9,147,147,144,138,129 %N A202698 The first of a set of three triangles constructed by the same rule as A202692-A202694, but where the top entries in the three triangles are 0,1,0 respectively. %H A202698 M. Josuat-Verges, J.-C. Novelli and J.-Y. Thibon, <a href="http://arxiv.org/abs/1110.5272">The algebraic combinatorics of snakes</a>, arXiv preprint arXiv:1110.5272, 2011 %e A202698 The triangle begins: %e A202698 0 %e A202698 0 0 %e A202698 3 3 3 %e A202698 0 3 6 9 %e A202698 147 147 144 138 129 %e A202698 ... %e A202698 The three triangles together: %e A202698 0 1 0 %e A202698 0 0 0 1 1 1 %e A202698 3 3 3 3 3 2 2 1 0 %e A202698 0 3 6 9 9 12 15 17 17 19 20 20 %e A202698 147 147 144 138 129 129 120 108 93 76 76 59 40 20 0 %Y A202698 The three triangles are A202698, A202699, A202700. %K A202698 nonn,tabl,more %O A202698 1,4 %A A202698 _N. J. A. Sloane_, Dec 23 2011