%I #7 Mar 22 2022 00:11:51
%S 1,2,4,3,6,8,5,9,7,12,10,13,11,16,14,17,15,20,18,21,19,24,22,25,23,28,
%T 26,29,27,32,30,33,31,36,34,37,35,40,38,41,39,44,42,45,43,48,46,49,47,
%U 52,50,53,51,56,54,57,55,60,58,61,59,64,62,65,63,68,66
%N Inverse permutation to A084385.
%C -4 <= a(n) - A084385(n) <= 3;
%C for n > 4: a(n) != A084385(n);
%C for n > 7: a(n) >= A084385(n) - 3.
%H Reinhard Zumkeller, <a href="/A261351/b261351.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o (Haskell)
%o import Data.List (elemIndex); import Data.Maybe (fromJust)
%o a261351 = (+ 1) . fromJust . (`elemIndex` a084385_list)
%Y Cf. A084385.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Aug 16 2015