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 A031329 #4 Mar 30 2012 18:56:23 %S A031329 11,17,18,38,39,50,62,81,92,100,104,119,134,138,146,164,174,185,192, %T A031329 196,199,201,202,208,217,244,259,262,285,328,329,337,346,377,381,395, %U A031329 405,422,429,473,474,476,492,496,499,510,515,522 %N A031329 Position of n-th 4 in A031324. %K A031329 nonn %O A031329 1,1 %A A031329 _Clark Kimberling_