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 A332512 #15 Dec 11 2024 06:37:09 %S A332512 13,21,26,28,35,36,37,39,42,45,52,56,57,61,63,65,70,72,73,74,76,77,78, %T A332512 84,90,91,93,95,97,99,104,105,108,109,111,112,114,117,119,122,124,126, %U A332512 129,130,133,135,140,143,144,146,147,148,152,153,154,155,156,157,161 %N A332512 Numbers k such that phi(k) == 0 (mod 12), where phi is the Euler totient function (A000010). %C A332512 Dence and Pomerance showed that the asymptotic number of the terms below x is ~ x. %H A332512 Amiram Eldar, <a href="/A332512/b332512.txt">Table of n, a(n) for n = 1..10000</a> %H A332512 Thomas Dence and Carl Pomerance, <a href="https://doi.org/10.1007/978-1-4757-4507-8_2">Euler's function in residue classes</a>, in: K. Alladi, P. D. T. A. Elliott, A. Granville and G. Tenenbaum (eds.), Analytic and Elementary Number Theory, Developments in Mathematics, Vol. 1, Springer, Boston, MA, 1998, pp. 7-20, <a href="https://math.dartmouth.edu/~carlp/PDF/paper116.pdf">alternative link</a>. %e A332512 13 is a term since phi(13) = 12 == 0 (mod 12). %t A332512 Select[Range[200], Divisible[EulerPhi[#], 12] &] %o A332512 (Magma) [k:k in [1..170]| EulerPhi(k) mod 12 eq 0]; // _Marius A. Burtea_, Feb 14 2020 %Y A332512 Cf. A000010, A008594, A332511, A332513, A332514, A332515, A332516. %K A332512 nonn %O A332512 1,1 %A A332512 _Amiram Eldar_, Feb 14 2020