A068975 Composite k such that (k+1) * Sum_{d|k} d/sigma(d) is an integer.

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

Offset

1,1

Comments

If k is prime, trivially (k+1) * Sum_{d|k} d/sigma(d) = 2k+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