OFFSET
1,1
COMMENTS
See A156595.
Numbers whose squarefree part is congruent modulo 9 to 2, 3, 5 or 8. - Peter Munn, May 17 2020
The asymptotic density of this sequence is 1/2. - Amiram Eldar, Mar 08 2021
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
(See A189715.)
f[p_, e_] := (p^Mod[e, 2]); sqfpart[n_] := Times @@ f @@@ FactorInteger[n]; Select[Range[160], MemberQ[{2, 3, 5, 8}, Mod[sqfpart[#], 9]] &] (* Amiram Eldar, Mar 08 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 26 2011
EXTENSIONS
Name enhanced by Peter Munn, May 17 2020
STATUS
approved