A055743 Phi(n) has fewer distinct prime divisors than n.
2, 6, 10, 12, 15, 20, 24, 30, 34, 40, 42, 48, 51, 60, 66, 68, 70, 78, 80, 84, 85, 90, 96, 102, 105, 110, 114, 120, 126, 130, 132, 136, 138, 140, 150, 156, 160, 165, 168, 170, 174, 180, 182, 190, 192, 195, 204, 210, 220, 222, 228, 230, 234, 238, 240, 246, 252
Offset: 1
Keywords
Examples
n=996 has 3 distinct prime divisors, 2, 3, and 83, while phi(996) = 328 = 2*2*2*41 has only 2 distinct prime factors.
Links
- Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Range[100], PrimeNu[EulerPhi[#]] < PrimeNu[#] &] (* G. C. Greubel, May 13 2017 *)
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PARI
is(n)=my(f=factor(n)); omega(eulerphi(f)) < #f~ \\ Charles R Greathouse IV, Mar 04 2017