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 A063989 Numbers with a prime number of prime divisors (counted with multiplicity). 9
 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: A077136 A098216 A063806 * 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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