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Infinitary nontotient numbers: values not in the range of the infinitary totient function iphi (A091732).
4

%I #10 Apr 22 2023 11:38:58

%S 5,7,9,11,13,14,17,19,21,23,25,26,27,29,31,33,34,35,37,38,39,41,43,47,

%T 49,50,51,53,55,57,59,61,62,63,65,67,68,69,71,73,74,75,76,77,79,81,83,

%U 85,86,87,89,91,93,94,95,97,98,99,101,103,105,107,109,110,111

%N Infinitary nontotient numbers: values not in the range of the infinitary totient function iphi (A091732).

%C Numbers k such that A091732(x) = k has no solution, i.e., A362485(k) = 0.

%C Most of the odd numbers are in this sequence. Odd numbers that are not here are 1, 3, 15, 45, 255, 765, 3825, 11475, 65535, 196605, 983025, ..., which are the values of iphi at powers of 2.

%H Amiram Eldar, <a href="/A362486/b362486.txt">Table of n, a(n) for n = 1..10000</a>

%F A362485(a(n)) = 0.

%t Select[Range[120], Length[invIPhi[#]] == 0 &] (* using the function invIPhi from A362484 *)

%Y Cf. A091732, A362484, A362485.

%Y Similar sequences: A005277, A005278, A347771, A362182.

%K nonn

%O 1,1

%A _Amiram Eldar_, Apr 22 2023