OFFSET
1,1
COMMENTS
If k is prime, trivially (k+1) * Sum_{d|k} d/sigma(d) = 2k+1 is an integer.
CROSSREFS
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