OFFSET
1,5
COMMENTS
The nomenclature of A159072 applies, where the terms in that sum are counted.
FORMULA
EXAMPLE
a(8) = 7 adds k = 6, where {1, 2, 3} is not a subset of the divisor set {1, 2, 4} of n = 8, and k = 1, with an empty proper divisor set.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 04 2009
EXTENSIONS
Edited by R. J. Mathar, Apr 06 2009
STATUS
approved