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A068975 Composite n such that (n+1)*sum(d|n,d/sigma(d)) is an integer (1 excluded). 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 n is prime, trivially (n+1)*sum(d|n,d/sigma(d))=2n+1 is an integer

LINKS

Table of n, a(n) for n=1..35.

CROSSREFS

Sequence in context: A124619 A290071 A221797 * A177709 A211503 A266104

Adjacent sequences:  A068972 A068973 A068974 * A068976 A068977 A068978

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 April 24 18:03 EDT 2019. Contains 322430 sequences. (Running on oeis4.)