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 A359565 #14 Feb 12 2023 20:51:52 %S A359565 12,24,36,40,48,60,72,80,84,96,108,120,126,132,144,156,160,168,180, %T A359565 192,200,204,216,228,240,252,264,276,280,288,300,312,320,324,336,348, %U A359565 360,364,372,378,384,396,400,408,420,432,440,444,456,468,480,492,504,516,520 %N A359565 Numbers that have at least three divisors with the same value of the Euler totient function (A000010). %C A359565 The least odd term is a(392) = 3591, the least term that is coprime to 6 is a(34211) = 305515, and the least term that is coprime to 30 is a(158487) = 1413797. %C A359565 If k is a term then all the multiples of k are terms. The primitive terms are in A359566. %C A359565 The numbers of terms not exceeding 10^k, for k = 1, 2, ..., are 0, 10, 108, 1104, 11181, 112092, 1121784, 11221475, 112227492, 1122320814, ... . Apparently, the asymptotic density of this sequence exists and equals 0.1122... . %H A359565 Amiram Eldar, <a href="/A359565/b359565.txt">Table of n, a(n) for n = 1..10000</a> %e A359565 12 is a term since its has 3 divisors, 3, 4 and 6, with the same value of the Euler totient function, 2. %t A359565 Select[Range[1, 10^5, 2], Max[Tally[EulerPhi[Divisors[#]]][[;; , 2]]] > 2 &] %o A359565 (PARI) is(k) = vecmax(matreduce(apply(x->eulerphi(x), divisors(k)))[,2]) > 2; %Y A359565 Cf. A000010, A326835, A359563, A359564, A359566. %K A359565 nonn %O A359565 1,1 %A A359565 _Amiram Eldar_, Jan 06 2023