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 A329180 #9 Nov 08 2019 09:46:43 %S A329180 0,2,1,3,8,10,4,11,6,7,5,9,12,14,13,15,32,34,16,35,40,42,18,43,19,24, %T A329180 17,26,44,46,27,47,28,30,20,31,33,36,22,38,23,25,21,29,39,41,37,45,48, %U A329180 50,49,51,56,58,52,59,54,55,53,57,60,62,61,63,128,130,64 %N A329180 Inverse permutation to A329101. %H A329180 Rémy Sigrist, <a href="/A329180/b329180.txt">Table of n, a(n) for n = 0..4095</a> %H A329180 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %e A329180 A329101(42) = 21, hence a(21) = 42. %Y A329180 Cf. A329101. %K A329180 nonn,base %O A329180 0,2 %A A329180 _Rémy Sigrist_, Nov 07 2019