|
Search: id:A068975
|
|
|
| A068975 |
|
Composite n such that (n+1)*sum(d|n,d/sigma(d)) is an integer (1 excluded). |
|
+0
1
|
|
| 39, 215, 623, 1023, 1343, 1455, 2303, 2431, 2519, 9503, 13039, 13055, 13319, 23759, 24479, 29183, 44863, 58463, 58559, 82583, 85359, 87295, 99863, 123463, 136079, 144143, 147455, 154623, 196095, 273023, 283727, 294839, 390239, 435455, 450743
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
If n is prime, trivially (n+1)*sum(d|n,d/sigma(d))=2n+1 is an integer
|
|
CROSSREFS
|
Adjacent sequences: A068972 A068973 A068974 this_sequence A068976 A068977 A068978
Sequence in context: A128826 A105838 A124619 this_sequence A101627 A070146 A061169
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 06 2002
|
|
EXTENSIONS
|
More terms from Lambert Klasen (Lambert.Klasen(AT)gmx.net), Jan 03 2005
|
|
|
Search completed in 0.002 seconds
|
