|
|
A193303
|
|
Squarefree numbers multiplied by powers of three.
|
|
1
|
|
|
1, 2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 26, 27, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 45, 46, 47, 51, 53, 54, 55, 57, 58, 59, 61, 62, 63, 65, 66, 67, 69, 70, 71, 73, 74, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89, 90, 91, 93
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
The asymptotic density of this sequence is 27/(4*Pi^2). - Amiram Eldar, Oct 01 2020
|
|
LINKS
|
|
|
MATHEMATICA
|
lim = 102; sf = Select[Range[lim], SquareFreeQ]; lim3 = 3^Range[0, Log[3, lim]]; Select[Union[Flatten[Outer[Times, sf, lim3]]], # <= lim &]
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|