OFFSET
1,1
COMMENTS
For all terms below 210 this sequence and A024619 are identical.
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
210 = 2*3*5*7 has 4 prime factors, hence it is not here, but it is part of A024619.
MAPLE
q:= n-> isprime(nops(ifactors(n)[2])):
select(q, [$1..210])[]; # Alois P. Heinz, Apr 18 2024
MATHEMATICA
Select[Range[200], PrimeQ[PrimeNu[#]] &] (* Paolo Xausa, Mar 28 2024 *)
PROG
(PARI) n=0; for (m=1, 10^9, if (isprime(omega(m)), write("b064040.txt", n++, " ", m); if (n==1000, break))) \\ Harry J. Smith, Sep 06 2009
(PARI) is(n)=isprime(omega(n)) \\ Charles R Greathouse IV, Sep 18 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Lior Manor, Aug 23 2001
EXTENSIONS
Edited by Charles R Greathouse IV, Mar 18 2010
Name edited by Michel Marcus, Oct 16 2023
STATUS
approved