A159074 - OEIS

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.

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

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

KEYWORD

nonn

AUTHOR

EXTENSIONS

Edited by R. J. Mathar, Apr 06 2009

STATUS

approved