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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
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: A341321 A063806 A323521 * A168645 A282668 A117097
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 18 2001
STATUS
approved

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Last modified February 25 13:12 EST 2024. Contains 370330 sequences. (Running on oeis4.)