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Numbers n such that sigma(n) = phi(n)*omega(n).
1

%I #15 Mar 04 2023 11:11:46

%S 35,357,3135,3339,5049,20026,23374,25714,33915,35074,35343,39105,

%T 39585,55154,56134,71145,124605,157586,316274,317205,373065,423045,

%U 435435,474548,479655,559845,596666,604012,696514,711988,819772,1123605,1161508,1277788,1491412

%N Numbers n such that sigma(n) = phi(n)*omega(n).

%H Donovan Johnson, <a href="/A073567/b073567.txt">Table of n, a(n) for n = 1..1000</a>

%t t = {}; Do[If[DivisorSigma[1, n] == EulerPhi[n]*PrimeNu[n], AppendTo[t, n]], {n,700000}]; t (* _Jayanta Basu_, Jul 01 2013 *)

%t Select[Range[15*10^5],DivisorSigma[1,#]==EulerPhi[#]PrimeNu[#]&] (* _Harvey P. Dale_, Mar 04 2023 *)

%o (PARI) for(n=1,10000000,if(sigma(n)==eulerphi(n)*omega(n),print1(n,","))) (Klasen)

%Y Cf. A000010, A000203, A001221.

%K easy,nonn

%O 1,1

%A _Benoit Cloitre_, Aug 31 2002

%E More terms from Lambert Klasen (lambert.klasen(AT)gmx.de), Dec 23 2004