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A063989 Numbers with a prime number of prime divisors (counted with multiplicity). 13
4, 6, 8, 9, 10, 12, 14, 15, 18, 20, 21, 22, 25, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 55, 57, 58, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 102, 105, 106 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MAPLE

with(numtheory); a := []: for i from 1 to 300 do if isprime(bigomega(i)) then a := [op(a), i]; fi; od: a;

MATHEMATICA

Select[Range[200], PrimeQ[PrimeOmega[#]]&] (* Harvey P. Dale, Jul 25 2015 *)

PROG

(PARI) n=0; for (m=1, 10^9, if (isprime(bigomega(m)), write("b063989.txt", n++, " ", m); if (n==1000, break))) \\ Harry J. Smith, Sep 05 2009

(PARI) is(n)=isprime(bigomega(n)) \\ Charles R Greathouse IV, Sep 18 2015

CROSSREFS

Sequence in context: A098216 A063806 A323521 * A168645 A282668 A117097

Adjacent sequences:  A063986 A063987 A063988 * A063990 A063991 A063992

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 18 2001

STATUS

approved

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Last modified November 22 06:26 EST 2019. Contains 329389 sequences. (Running on oeis4.)