20210628, 20:14  #1 
Jun 2012
Boulder, CO
3×109 Posts 
Announcing a new Wagstaff PRP
(2^15135397+1)/3 is a Fermat Probable prime! (4556209 decimal digits)
Also submitted to PRPTop. I am searching the range n=13M .. 17M currently, and nearly done. No other discoveries as of yet. 
20210628, 21:19  #2 
Sep 2002
Database er0rr
111100011101_{2} Posts 

20210628, 23:38  #3 
Sep 2006
The Netherlands
305_{16} Posts 
That's a very lucky find! Congrats on that one!
Had you asked me i would've guessed next one might've lurked at 30M earliest and 70M latest. 
20210629, 11:29  #4 
Feb 2017
Nowhere
4,993 Posts 

20210629, 13:24  #5 
Jun 2012
Boulder, CO
3·109 Posts 

20210629, 15:32  #6  
Feb 2017
Nowhere
4,993 Posts 
Quote:
Silly me, I failed to consider that you had tested multiple bases. Of course, these numbers automatically "pass" the test to base 2. Paper and pencil suffices for this one. If p > 3 is prime, N = (2^p + 1)/3, then (N1)/2 = (2^(p1)  1)/3 is odd and divisible by p, so N = (2^p + 1)/3 divides 2^p + 1, and 2^p + 1 divides 2^((N1)/2) + 1, so N divides 2^((N1)/2) + 1. Now 2^((N1)/2) + 1 divides 2^(N1)  1, so N divides 2^(N1) 1, but does not divide 2^((N1)/2)  1. 

20210629, 16:59  #7  
"99(4^34019)99 palind"
Nov 2016
(P^81993)SZ base 36
5760_{8} Posts 
Quote:


20210629, 17:02  #8  
"99(4^34019)99 palind"
Nov 2016
(P^81993)SZ base 36
2^{4}·191 Posts 
Quote:
Last fiddled with by sweety439 on 20210629 at 17:02 

20210629, 20:23  #9  
Mar 2019
2^{3}×5^{2} Posts 
Quote:
Maybe a mod can ban this guy until he stops flooding the forum with requests for other people to do things. 

20210629, 20:37  #10  
Sep 2002
Database er0rr
53·73 Posts 
Quote:
Last fiddled with by paulunderwood on 20210629 at 20:38 

20210629, 21:33  #11 
"Curtis"
Feb 2005
Riverside, CA
4,999 Posts 
We gave him some time off to consider his behavior, and it hasn't changed much. I suppose your suggestion and this reply might be considered yet another warning to Sweety before the banhammer falls again.

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Status of Wagstaff testing? and testing Mersenne primes for Wagstaffness  GP2  Wagstaff PRP Search  414  20201227 08:11 
announcing 86,225,219 is exponent for next Prime  eight6225219  Miscellaneous Math  7  20191121 14:59 
Announcing GIMPS Visualization Tool 2.1  chalsall  Data  5  20121231 15:57 
Announcing GIMPS Visualization Tool 2.0  chalsall  Data  25  20110125 07:00 
Announcing the release of Triance OS 1.0BETA  zariss  Linux  1  20040823 21:42 