OFFSET
1,2
COMMENTS
The asymptotic density of this sequence is 15/(2*Pi^2) (A323669). - Amiram Eldar, May 10 2022
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
Union[Join[{9, 18}, Select[Range[100], (e = IntegerExponent[#, 2]) <= 3 && SquareFreeQ[#/2^e] &]]] (* Amiram Eldar, May 10 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 13 2006
STATUS
approved