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 A116627 #7 Mar 31 2012 13:21:11 %S A116627 1,3,2,5,9,4,15,7,17,11,23,6,8,16,10,13,19,25,29,33,41,37,14,18,24,12, %T A116627 49,45,53,63,57,21,27,35,31,47,59,55,67,39,43,71,22,75,79,85,89,30,20, %U A116627 28,26,36,44,34,32,46,56,58,54,42,40,38,48,51,61,65,73,69,81,77,95,87 %N A116627 a(n) = First integer i such that A116626(i) = n, 0 if n never occurs in A116626. %C A116627 If A116626 is really a permutation of natural numbers, then this is as well and no zeros are needed. %H A116627 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A116627 Inverse: A116626. %K A116627 nonn %O A116627 1,2 %A A116627 _Paul D. Hanna_ and _Antti Karttunen_, Feb 21 2006