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A070011 Numbers n such that number of prime factors divided by the number of distinct prime factors is not an integer. 7

%I

%S 12,18,20,28,44,45,48,50,52,60,63,68,72,75,76,80,84,90,92,98,99,108,

%T 112,116,117,120,124,126,132,140,147,148,150,153,156,162,164,168,171,

%U 172,175,176,180,188,192,198,200,204,207,208,212,220,228,234,236,242

%N Numbers n such that number of prime factors divided by the number of distinct prime factors is not an integer.

%H Enrique Pérez Herrero, <a href="/A070011/b070011.txt">Table of n, a(n) for n = 1..5000</a>

%F A001222(n)/A001221(n) (i.e. bigomega(n)/omega(n)) is not an integer.

%e 45 is a term because 45 = 3^2 * 5 gives bigomega(45)=3 and omega(45)=2 and 3/2 is not an integer.

%t Select[Range[2,1000],!IntegerQ[PrimeOmega[#]/PrimeNu[#]]&] (* _Enrique Pérez Herrero_, Dec 20 2012 *)

%o (PARI) v=[]; for(n=2,300,if(denominator(bigomega(n)/omega(n))<>1,v=concat(v,n))); v

%o (PARI) is(n)=my(f=factor(n)[,2]); n>9 && vecsum(f)%#f!=0 \\ _Charles R Greathouse IV_, Oct 16 2015

%Y Cf. A067340 (complement), A070012 (floor(bigomega(n)/omega(n)).

%Y Different from A084679.

%K nonn

%O 1,1

%A _Rick L. Shepherd_, Apr 11 2002

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Last modified July 8 08:08 EDT 2020. Contains 335520 sequences. (Running on oeis4.)