This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A350316 #14 Jul 19 2024 08:47:05 %S A350316 1,30,58,78,82,106,130,138,150,172,178,198,222,226,238,268,282,316, %T A350316 342,358,366,378,382,388,418,438,462,478,498,502,506,508,546,562,570, %U A350316 598,606,618,630,642,646,652,658,682,690,718,738,742,772,786,810,826,838 %N A350316 Totient numbers k such that 3*k is a nontotient. %H A350316 Amiram Eldar, <a href="/A350316/b350316.txt">Table of n, a(n) for n = 1..10000</a> %e A350316 30 is a term since 30 = phi(31) = phi(62), but phi(n) = 3*30 = 90 has no solution. %e A350316 58 is a term since 58 = phi(59) = phi(118), but phi(n) = 3*58 = 174 has no solution. %o A350316 (PARI) isA350316(n) = istotient(n) && !istotient(3*n) %Y A350316 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 A350316 Cf. A002202, A005277. %K A350316 nonn %O A350316 1,2 %A A350316 _Jianing Song_, Dec 24 2021