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 A099424 #6 Mar 30 2012 18:50:48 %S A099424 1,2,3,5,4,7,8,9,6,11,12,13,14,15,10,17,18,19,20,21,22,23,24,25,26,27, %T A099424 16,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50, %U A099424 51,28,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73 %N A099424 Inverse of A060000. %C A099424 Permutation of the natural numbers. %H A099424 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A099424 nonn %O A099424 1,2 %A A099424 _Reinhard Zumkeller_, Oct 15 2004