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 A031319 #4 Mar 30 2012 18:56:23 %S A031319 56,58,60,62,64,187,190,193,196,199,337,340,343,346,349,487,490,493, %T A031319 496,499,637,640,643,646,649,787,790,793,796,799,846,849,852,855,858, %U A031319 861,864,867,870,873,876,879,882,885,888,891,894 %N A031319 Position of n-th 6 in A031312. %K A031319 nonn %O A031319 1,1 %A A031319 _Clark Kimberling_