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 A113323 #6 Mar 30 2012 18:50:53 %S A113323 1,2,3,4,5,6,12,9,10,7,11,8,22,14,25,17,18,19,33,13,35,15,24,16,43,27, %T A113323 46,30,31,20,32,21,56,23,37,38,39,40,67,26,69,28,45,29,77,48,80,51,52, %U A113323 53,88,34,90,36,58,59,60,61,101,64,65,41,66,42,111,44,71,72,73,74,122 %N A113323 A113321(A113321(n)). %C A113323 Inverse integer permutation of A113325; %C A113323 A113324(a(n)) = a(A113324(n)) = A113321(n). %H A113323 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A113323 nonn %O A113323 1,2 %A A113323 _Reinhard Zumkeller_, Oct 26 2005