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A234286
Positive odd numbers n such that 2m - sigma(m) is never equal to n, where sigma(.) is the sum of divisors function A000203. Conjectural.
4
3, 9, 13, 15, 17, 21, 23, 27, 29, 31, 33, 35, 39, 43, 45, 49
OFFSET
1,1
COMMENTS
The terms shown here are conjectural, based on a search up to 10^20 made by Davis et al. (2013).
LINKS
Nichole Davis, Dominic Klyve and Nicole Kraght, On the difference between an integer and the sum of its proper divisors, Involve, Vol. 6 (2013), No. 4, 493-504; DOI: 10.2140/involve.2013.6.493
CROSSREFS
Cf. A000203, A033879 (2n - sigma(n)).
For negative values of n see A234285.
Sequence in context: A070353 A029458 A050571 * A193927 A111230 A046865
KEYWORD
nonn,more,hard
AUTHOR
N. J. A. Sloane, Dec 28 2013
STATUS
approved