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 A209985 #5 Mar 30 2012 18:58:16 %S A209985 0,1,23,39,71,103,151,199,263,311,407,487,551,647,791,855,983,1111, %T A209985 1255,1399,1527,1623,1863,2039,2167,2327,2615,2759,2951,3175,3367, %U A209985 3607,3863,4023,4407,4599,4791,5079,5511,5703,5959 %N A209985 (A209984)/4. %C A209985 See A210000 for a guide to related sequences. %t A209985 (See the Mathematica section at A209981.) %Y A209985 Cf. A210000. %K A209985 nonn %O A209985 0,3 %A A209985 _Clark Kimberling_, Mar 17 2012