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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
12, 18, 20, 28, 44, 45, 48, 50, 52, 60, 63, 68, 72, 75, 76, 80, 84, 90, 92, 98, 99, 108, 112, 116, 117, 120, 124, 126, 132, 140, 147, 148, 150, 153, 156, 162, 164, 168, 171, 172, 175, 176, 180, 188, 192, 198, 200, 204, 207, 208, 212, 220, 228, 234, 236, 242 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Enrique Pérez Herrero, Table of n, a(n) for n = 1..5000

FORMULA

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

EXAMPLE

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

MATHEMATICA

Select[Range[2, 1000], !IntegerQ[PrimeOmega[#]/PrimeNu[#]]&] (* Enrique Pérez Herrero, Dec 20 2012 *)

PROG

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

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

CROSSREFS

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

Different from A084679.

Sequence in context: A253388 A030515 A162947 * A084679 A072588 A267117

Adjacent sequences:  A070008 A070009 A070010 * A070012 A070013 A070014

KEYWORD

nonn

AUTHOR

Rick L. Shepherd, Apr 11 2002

STATUS

approved

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Last modified January 22 18:06 EST 2019. Contains 319365 sequences. (Running on oeis4.)