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 A308541 #12 Jun 08 2019 03:56:22 %S A308541 1,2,6,3,9,7,11,4,13,10,15,8,16,12,17,5,18,14,19,20,26,21,61,22,38,23, %T A308541 28,24,67,25,73,27,30,29,42,31,78,39,32,34,81,33,84,35,40,62,87,36,51, %U A308541 44,43,37,89,47,45,41,74,68,92,46,95,97,54,52,48,49,99 %N A308541 Inverse permutation to A308539. %H A308541 Rémy Sigrist, <a href="/A308541/b308541.txt">Table of n, a(n) for n = 1..10000</a> %H A308541 Rémy Sigrist, <a href="/A308541/a308541.gp.txt">PARI program for A308541</a> %H A308541 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %e A308541 A308539(33) = 42, hence a(42) = 33. %o A308541 (PARI) See Links section. %Y A308541 Cf. A308539. %K A308541 nonn,base %O A308541 1,2 %A A308541 _Rémy Sigrist_, Jun 06 2019