login
This site is supported by donations to The OEIS Foundation.

 

Logo

Many excellent designs for a new banner were submitted. We will use the best of them in rotation.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified April 17 07:07 EDT 2014. Contains 240634 sequences.