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 A031321 #4 Mar 30 2012 18:56:23 %S A031321 76,78,80,82,84,217,220,223,226,229,367,370,373,376,379,517,520,523, %T A031321 526,529,667,670,673,676,679,817,820,823,826,829,967,970 %N A031321 Position of n-th 8 in A031312. %K A031321 nonn %O A031321 1,1 %A A031321 _Clark Kimberling_