|
| |
|
|
A159074
|
|
Sum of the k in the range 1<=k<=n such that set of proper divisors of k is not a subset of the set of proper divisors of n.
|
|
0
|
|
|
|
1, 1, 1, 1, 5, 1, 11, 7, 19, 24, 38, 11, 50, 46, 55, 67, 95, 76, 113, 91, 124, 150, 176, 121, 200, 221, 242, 252, 306, 237
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,5
|
|
|
COMMENTS
|
The nomenclature of A159072 applies, where the terms in that sum are counted.
|
|
|
LINKS
|
Table of n, a(n) for n=1..30.
|
|
|
FORMULA
|
a(n) = A158976(n) + 1.
If p = prime, a(p) = A000217(p) - A158662(p) + 1 = A000217(p) - A014284[A036234(p)] + 1.
a(n)+A159073(n)=A000217(n). - R. J. Mathar, Apr 06 2009
|
|
|
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
|
Cf.: A158976, A000217, A000040, A014284, A036234.
Sequence in context: A185953 A075677 A051853 * A147414 A117637 A113261
Adjacent sequences: A159071 A159072 A159073 * A159075 A159076 A159077
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Jaroslav Krizek, Apr 04 2009
|
|
|
EXTENSIONS
|
Edited by R. J. Mathar, Apr 06 2009
|
|
|
STATUS
|
approved
|
| |
|
|
