Numbers with sum free sets of primitive roots

[franktaw at netscape.net]

Suppose we look at the primitive roots of primes.  Which of these are sum free?  (All are product free, except p=2.)  Checking for p<100, I find that only 2, 3, 5, 7, and 13 are sum free.  I doubt that there are any more, but I don't see any way to prove it.
 
Franklin T. Adams-Watters
16 W. Michigan Ave.
Palatine, IL 60067
847-776-7645
 
 
-----Original Message-----
From: Edwin Clark <eclark at math.usf.edu>
To: jens at voss-ahrensburg.de
Cc: Sequence Fans <seqfan at ext.jussieu.fr>
Sent: Tue, 17 Jan 2006 15:40:42 -0500 (EST)
Subject: Re: Numbers with anticlosed sets of non-squares


On Tue, 17 Jan 2006 jens at voss-ahrensburg.de wrote:

> Let R be a ring. We will call a subset T of R *anticlosed* if for any
> elements t1 and t2 of T, neither the sum t1 + t2 nor the product t1 * t2
> lies in T.

I suggest that you call such a subset "sum and product free".
___________________________________________________
Try the New Netscape Mail Today!
Virtually Spam-Free | More Storage | Import Your Contact List
http://mail.netscape.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.seqfan.eu/pipermail/seqfan/attachments/20060119/958f537e/attachment-0001.htm>