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%I #14 Jul 19 2024 08:47:05
%S 1,30,58,78,82,106,130,138,150,172,178,198,222,226,238,268,282,316,
%T 342,358,366,378,382,388,418,438,462,478,498,502,506,508,546,562,570,
%U 598,606,618,630,642,646,652,658,682,690,718,738,742,772,786,810,826,838
%N Totient numbers k such that 3*k is a nontotient.
%H Amiram Eldar, <a href="/A350316/b350316.txt">Table of n, a(n) for n = 1..10000</a>
%e 30 is a term since 30 = phi(31) = phi(62), but phi(n) = 3*30 = 90 has no solution.
%e 58 is a term since 58 = phi(59) = phi(118), but phi(n) = 3*58 = 174 has no solution.
%o (PARI) isA350316(n) = istotient(n) && !istotient(3*n)
%Y Totient numbers k such that m*k is a nontotient: this sequence (m=3), A350317 (m=5), A350318 (m=7), A350319 (m=9), A350320 (m=10), A350321 (m=14).
%Y Cf. A002202, A005277.
%K nonn
%O 1,2
%A _Jianing Song_, Dec 24 2021