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 A102512 #6 Mar 30 2012 18:50:48 %S A102512 1,2,10,4,6,14,3,8,9,11,5,12,21,7,17,16,15,18,26,20,13,33,22,24,25,35, %T A102512 27,28,19,30,23,32,38,34,39,36,29,37,31,40,42,46,43,44,45,41,47,48,49, %U A102512 50,51,52,58,54,55,56,53,57,65,60,62,61,63,64,59,74,69,68,82,66,71,72 %N A102512 A102510(A102510(n)). %H A102512 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A102512 nonn %O A102512 1,2 %A A102512 _Reinhard Zumkeller_, Jan 13 2005