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 A238862 #21 Jul 05 2014 11:12:02 %S A238862 1,2,3,4,6,7,5,9,11,8,10,12,14,15,13,18,20,16,24,19,17,21,23,25,22,27, %T A238862 29,26,28,30,32,33,31,35,37,38,36,41,43,39,47,51,34,40,42,44,46,48,45, %U A238862 50,52,49,53,55,57,54,58,60,61,56,65,63,66,59,64,69,72 %N A238862 Inverse permutation to A239965. %C A238862 a(A239965(n)) = A239965(a(n)) = n; %C A238862 A018252(a(n)) = A240024(n). %H A238862 Reinhard Zumkeller, <a href="/A238862/b238862.txt">Table of n, a(n) for n = 1..10000</a> %H A238862 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A238862 (Haskell) %o A238862 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A238862 a238862 = (+ 1) . fromJust . (`elemIndex` a239965_list) %Y A238862 Cf. A239943 (fixed points). %K A238862 nonn %O A238862 1,2 %A A238862 _Reinhard Zumkeller_, Apr 30 2014