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 A102513 #6 Mar 30 2012 18:50:48 %S A102513 1,2,5,4,7,3,11,8,9,6,14,12,17,10,13,16,21,18,23,20,15,19,29,24,25,22, %T A102513 27,28,31,34,37,32,26,30,33,36,39,35,38,40,42,46,51,44,45,41,55,48,49, %U A102513 50,43,52,58,54,47,56,53,57,61,60,65,59,63,64,62,67,70,68,66,73,77,72 %N A102513 Inverse permutation to A102510. %H A102513 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A102513 nonn %O A102513 1,2 %A A102513 _Reinhard Zumkeller_, Jan 13 2005