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 A225047 #7 Mar 22 2022 00:10:47 %S A225047 1,2,3,5,4,6,7,9,10,12,8,13,11,16,17,19,14,20,15,23,21,24,18,28,22,27, %T A225047 25,31,26,36,29,32,33,35,30,40,34,39,37,43,38,44,41,47,48,50,42,54,45, %U A225047 51,49,55,46,58,52,59,53,62,56,63,57,66,64,67,60,71,61 %N A225047 Inverse permutation to A121216. %C A225047 A121216(a(n)) = a(A121216(n)) = n. %H A225047 Reinhard Zumkeller, <a href="/A225047/b225047.txt">Table of n, a(n) for n = 1..10000</a> %H A225047 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A225047 (Haskell) %o A225047 import Data.List (elemIndex) %o A225047 import Data.Maybe (fromJust) %o A225047 a225047 = (+ 1) . fromJust . (`elemIndex` a121216_list) %K A225047 nonn %O A225047 1,2 %A A225047 _Reinhard Zumkeller_, Apr 25 2013