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A068975 Composite k such that (k+1) * Sum_{d|k} d/sigma(d) is an integer. 0
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; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If k is prime, trivially (k+1) * Sum_{d|k} d/sigma(d) = 2k+1 is an integer.
LINKS
CROSSREFS
Sequence in context: A124619 A290071 A221797 * A177709 A211503 A266104
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 06 2002
EXTENSIONS
More terms from Lambert Klasen (Lambert.Klasen(AT)gmx.net), Jan 03 2005
STATUS
approved

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Last modified May 24 18:59 EDT 2024. Contains 372781 sequences. (Running on oeis4.)