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 A166016 #7 Mar 20 2022 21:42:32 %S A166016 1,4,2,3,5,6,7,8,11,12,9,10,13,14,16,17,15,22,18,19,23,24,20,21,25,26, %T A166016 29,30,27,28,31,32,37,38,33,34,39,40,35,36,41,42,46,47,43,44,48,49,45, %U A166016 56,50,51,57,58,52,53,59,60,54,55,61,62,67,68,63,64,69,70,65,66,71,72 %N A166016 Inverse permutation to A138609. %H A166016 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A166016 Inverse: A138609. %K A166016 nonn %O A166016 1,2 %A A166016 _Antti Karttunen_, Oct 05 2009