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Inverse permutation to A269838.
2

%I #10 Jul 04 2022 13:57:11

%S 1,2,3,4,5,6,9,8,7,10,17,11,33,18,13,12,65,14,129,20,19,34,257,16,21,

%T 66,15,25,513,22,1025,24,35,130,37,23,2049,258,67,26,4097,38,8193,36,

%U 29,514,16385,27,41,42,131,68,32769,30,49,40,259,1026

%N Inverse permutation to A269838.

%H Rémy Sigrist, <a href="/A355405/b355405.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A355405/a355405.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(n)) = 2^(n-1) + 1 (where prime(n) denotes the n-th prime number).

%e A269838(38) = 42, so a(42) = 38.

%o (PARI) See Links section.

%Y Cf. A269838.

%K nonn

%O 1,2

%A _Rémy Sigrist_, Jul 01 2022