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 A260161 #18 Jan 09 2016 12:25:45 %S A260161 1,2,2,3,6,56,55525372 %N A260161 a(n) is the a(n-1)-th a(n-2)-dimensional simplex number, starting with the terms 1, 2. %C A260161 The next term is too large to include. %H A260161 OEIS Wiki, <a href="http://oeis.org/wiki/Simplicial_polytopic_numbers">Simplicial polytopic numbers</a> %e A260161 56 is the 6th 3-simplex (or tetrahedral) number = A000292(6). %e A260161 55525372 is the 56th 6-simplex number = A000579(61). %e A260161 The next term will be the 55525372th 56-simplex number. %Y A260161 Cf. A000217, A000292, A000579. %K A260161 nonn %O A260161 1,2 %A A260161 _Robin Powell_, Nov 09 2015