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 A350319 #13 Jul 19 2024 08:47:15 %S A350319 1,10,46,66,78,106,126,138,150,166,178,190,210,226,262,268,270,306, %T A350319 346,358,366,372,378,382,418,430,442,466,478,490,506,522,546,570,586, %U A350319 598,606,630,646,676,682,718,726,738,750,786,810,822,826,838,882,886,906 %N A350319 Totient numbers k such that 9*k is a nontotient. %H A350319 Amiram Eldar, <a href="/A350319/b350319.txt">Table of n, a(n) for n = 1..10000</a> %e A350319 10 is a term since 10 = phi(11) = phi(22), but phi(n) = 9*10 = 90 has no solution. %e A350319 46 is a term since 46 = phi(47) = phi(94), but phi(n) = 9*46 = 414 has no solution. %o A350319 (PARI) isA350319(n) = istotient(n) && !istotient(9*n) %Y A350319 Totient numbers k such that m*k is a nontotient: A350316 (m=3), A350317 (m=5), A350318 (m=7), this sequence (m=9), A350320 (m=10), A350321 (m=14). %Y A350319 Cf. A002202, A005277. %K A350319 nonn %O A350319 1,2 %A A350319 _Jianing Song_, Dec 24 2021