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 A015732 #22 Dec 05 2024 10:47:52 %S A015732 8,10,18,24,26,28,30,34,40,52,56,58,70,72,74,76,78,82,84,88,90,98,102, %T A015732 104,106,108,110,120,122,124,126,128,130,136,140,146,148,152,156,168, %U A015732 170,172,174,176,178,182,184,190,194,198,202,210,218,222,224,226,228 %N A015732 Even numbers k such that d(k) | phi(k). %H A015732 Amiram Eldar, <a href="/A015732/b015732.txt">Table of n, a(n) for n = 1..10000</a> %t A015732 Select[Range[0, 250, 2], Divisible[EulerPhi[#], DivisorSigma[0, #]] &] (* _Amiram Eldar_, Dec 05 2024 *) %o A015732 (PARI) is(k) = if(k % 2, 0, my(f = factor(k)); !(eulerphi(f) % numdiv(f))); \\ _Amiram Eldar_, Dec 05 2024 %Y A015732 Subsequence of A020491. %Y A015732 Cf. A000005 (d), A000010 (phi). %K A015732 nonn %O A015732 1,1 %A A015732 _Robert G. Wilson v_