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Revision History for A069059

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Showing entries 1-10 | older changes
Numbers k such that k and sigma(k) are not relatively prime.
(history; published version)
#26 by Alois P. Heinz at Mon May 23 11:46:14 EDT 2022
STATUS

proposed

approved

#25 by Amiram Eldar at Mon May 23 11:25:38 EDT 2022
STATUS

editing

proposed

#24 by Amiram Eldar at Mon May 23 10:49:46 EDT 2022
COMMENTS

A009194(a(n)) > 1. - Reinhard Zumkeller, Mar 23 2013

FORMULA

A009194(a(n)) > 1. - Reinhard Zumkeller, Mar 23 2013

#23 by Amiram Eldar at Mon May 23 10:49:19 EDT 2022
NAME

Numbers n k such that n k and sigma(nk) are not relatively prime.

CROSSREFS
#22 by Amiram Eldar at Mon May 23 10:48:55 EDT 2022
COMMENTS

The asymptotic density of this sequence is 1 (Dressler, 1974; Luca, 2007). - Amiram Eldar, May 23 2022

LINKS

Robert E. Dressler, <a href="https://doi.org/10.4153/CMB-1974-019-5">On a theorem of Niven</a>, Canadian Mathematical Bulletin, Vol. 17, No. 1 (1974), pp. 109-110.

Florian Luca, <a href="http://projecteuclid.org/euclid.mjms/1316032973">On the densities of some subsets of integers</a>, Missouri Journal of Mathematical Sciences, Vol. 19, No. 3 (2007), pp. 167-170.

STATUS

approved

editing

#21 by Michel Marcus at Wed Sep 02 09:14:19 EDT 2015
STATUS

reviewed

approved

#20 by Joerg Arndt at Wed Sep 02 05:27:36 EDT 2015
STATUS

proposed

reviewed

#19 by Robert Israel at Tue Sep 01 15:25:53 EDT 2015
STATUS

editing

proposed

#18 by Robert Israel at Tue Sep 01 15:25:44 EDT 2015
MAPLE

select(n -> igcd(n, numtheory:-sigma(n)) > 1, [$1..1000]); # Robert Israel, Sep 01 2015

STATUS

proposed

editing

#17 by Wesley Ivan Hurt at Tue Sep 01 14:16:48 EDT 2015
STATUS

editing

proposed