|
| |
|
|
A056913
|
|
Odd squarefree numbers for which the number of prime divisors is even.
|
|
7
|
|
|
|
1, 15, 21, 33, 35, 39, 51, 55, 57, 65, 69, 77, 85, 87, 91, 93, 95, 111, 115, 119, 123, 129, 133, 141, 143, 145, 155, 159, 161, 177, 183, 185, 187, 201, 203, 205, 209, 213, 215, 217, 219, 221, 235, 237, 247, 249, 253, 259, 265, 267, 287, 291, 295, 299, 301, 303
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Liouville function lambda(n) (A008836) is positive.
|
|
|
REFERENCES
|
H. Gupta, A formula for L(n), J. Indian Math. Soc., 7 (1943), 68-71.
|
|
|
LINKS
|
Table of n, a(n) for n=1..56.
|
|
|
MATHEMATICA
|
f[n_]:=Last/@FactorInteger[n]=={1, 1}&&FactorInteger[n][[1, 1]]>2; a=6; lst={1}; Do[If[f[n], AppendTo[lst, n]], {n, 6!}]; lst (* From Vladimir Orlovsky, Nov 23 2009 *)
|
|
|
CROSSREFS
|
Cf. A056911, A056912, A008836, A026424, A028260.
Sequence in context: A146166 A024556 A046388 * A002557 A128907 A225709
Adjacent sequences: A056910 A056911 A056912 * A056914 A056915 A056916
|
|
|
KEYWORD
|
easy,nonn
|
|
|
AUTHOR
|
James A. Sellers, Jul 07 2000
|
|
|
STATUS
|
approved
|
| |
|
|
