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 A117924 #6 Mar 30 2012 18:50:54 %S A117924 1,2,3,4,5,6,7,8,9,10,15,12,17,14,11,16,13,18,19,20,21,22,23,24,25,36, %T A117924 27,28,29,32,31,40,33,26,35,38,43,30,41,34,39,42,37,44,51,52,55,48,47, %U A117924 50,53,54,45,46,49,56,57,66,63,70,69,62,71,60,59,72,73,68,67,64,65,58 %N A117924 A117922(A117922(n)). %C A117924 a(n) = A117923(n) for n<= 25; %C A117924 Permutation of the natural numbers, inverse: A117923; %C A117924 fixed points: A117925. %H A117924 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A117924 nonn %O A117924 1,2 %A A117924 _Reinhard Zumkeller_, Apr 03 2006