%I #11 Apr 25 2024 09:11:26
%S 1,2,3,4,5,6,9,8,7,10,17,11,33,18,13,16,65,14,129,12,19,34,257,20,21,
%T 66,15,25,513,22,1025,32,35,130,37,23,2049,258,67,24,4097,38,8193,36,
%U 29,514,16385,27,41,26,131,68,32769,30,49,40,259,1026,65537,28
%N Inverse permutation to A371985.
%H Rémy Sigrist, <a href="/A372166/a372166_1.gp.txt">PARI program</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F a(prime(k)) = 2^(k-1) + 1 for any k > 0 (where prime(k) denotes the k-th prime number).
%e A371985(42) = 70, so a(70) = 42.
%o (PARI) \\ See Links section.
%Y Cf. A355405, A371985.
%K nonn
%O 1,2
%A _Rémy Sigrist_, Apr 21 2024