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.

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

Table of n, a(n) for n=1..16.

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

Adjacent sequences: A234283 A234284 A234285 * A234287 A234288 A234289

Keyword

nonn,more,hard

Author

N. J. A. Sloane, Dec 28 2013

Status

approved