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 A175785 #26 Dec 29 2019 16:34:52 %S A175785 30,60,66,102,110,120,132,138,150,165,170,174,204,220,230,240,246,255, %T A175785 264,276,282,290,300,318,340,345,348,354,374,408,410,426,435,440,460, %U A175785 470,480,492,498,506,528,530,534,550,552,561,564,580,590,600,606,615 %N A175785 Numbers n such that the number of distinct prime divisors of n does not divide phi(n). %C A175785 a(n) gives the integers where omega(n) = A001221(n) does not divide phi(n) = A000010(n). %C A175785 This sequence does not contain any prime powers (A000961), nor any numbers with only two distinct prime divisors (A007774); so it is a subsequence of A000977. %H A175785 Enrique Pérez Herrero, <a href="/A175785/b175785.txt">Table of n, a(n) for n = 1..10000</a> %e A175785 30 is in this sequence because omega(30)=3 does not divide phi(30)=8. %t A175785 Select[Range[2,700],Mod[EulerPhi[#],PrimeNu[#]]!=0&] (* _Harvey P. Dale_, Dec 29 2019 *) %o A175785 (PARI) isok(n) = (eulerphi(n) % omega(n) != 0) \\ _Michel Marcus_, Jun 12 2013 %Y A175785 Cf. A001221, A000010, A075592, A109425, A109427, A192218, A000977, A000961, A007774. %K A175785 nonn %O A175785 1,1 %A A175785 _Enrique Pérez Herrero_, Sep 04 2010