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 A066254 #6 Mar 30 2012 18:50:19 %S A066254 1,2,3,4,5,6,7,8,9,10,11,12,16,13,15,14,24,18,17,30,34,20,19,21,42,46, %T A066254 23,22,52,26,25,27,60,29,66,28,70,31,76,32,80,36,33,35,88,38,92,37,98, %U A066254 39,41,40,106,110,43,116,45,44,122,48,126,47,132,136,140,50,49,146,51 %N A066254 a(n) = A066250(A066250(n)). %C A066254 Permutation of natural numbers. %H A066254 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A066254 nonn %O A066254 1,2 %A A066254 _Reinhard Zumkeller_, Dec 09 2001