20210104, 01:14  #331 
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
10713_{8} Posts 
Odd Comm message
Code:
[Comm thread Jan 3 15:39] Updating computer information on the server [Comm thread Jan 3 15:39] Done communicating with server. [Comm thread Jan 3 18:32] Sending result to server: UID: petrw1/Speck, M41791891 completed P1, B1=1000000, B2=30000000, Wi4: 38F4559E [Comm thread Jan 3 18:32] [Comm thread Jan 3 18:32] PnErrorResult value missing. Full response was: [Comm thread Jan 3 18:32] [Jan 3 18:32] Visit http://mersenneforum.org for help. [Comm thread Jan 3 18:32] Will try contacting server again in 70 minutes. 
20210104, 02:37  #332 
P90 years forever!
Aug 2002
Yeehaw, FL
3·11·223 Posts 
30.4 build 5 released. Please post new comments about version 30.4 (any build) to this thread: https://www.mersenneforum.org/showth...252#post568252
We know return this thread to its normal function of finding lots of new factors. Thanks again for everyone's help. 
20210108, 13:02  #333 
Apr 2010
Over the rainbow
2×5×11×23 Posts 
Taking 27.1M for a spin.
Started 5 days ago, I got some good result last night Code:
. [Fri Jan 8 04:03:01 2021] P1 found a factor in stage #2, B1=1350000, B2=89100000. UID: firejuggler/Maison, M27152453 has a factor: 214211625581311913643047 (P1, B1=1350000, B2=89100000) [Fri Jan 8 05:29:00 2021] P1 found a factor in stage #1, B1=1350000. UID: firejuggler/Maison, M27153151 has a factor: 4694191350737025517407343 (P1, B1=1350000) [Fri Jan 8 06:41:42 2021] P1 found a factor in stage #1, B1=1350000. UID: firejuggler/Maison, M27153359 has a factor: 26637694127747536479168769 (P1, B1=1350000) 3 factors found, on the same computer, on the same night. 
20210108, 15:13  #334  
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
10713_{8} Posts 
Quote:


20210112, 20:07  #335 
Jan 2021
2_{10} Posts 
Hey all!
Newbie to GIMPS here, been spending probably way to much time reading up and messing around with the tools over the last few days. I ended up finding this thread and started testing things at M16.34 I'm currently running mfakto and going from bit level 69 to 70 on that range, is that appropriate? In any case I've just found a first factor! Code:
found 1 factor for M16341833 from 2^69 to 2^70 (partially tested) [mfakto 0.15pre7MGW cl_barrett15_71_gs_2] tf(): total time spent: 2m 8.875s (1880.09 GHzdays / day) 
20210112, 23:30  #336  
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
5·911 Posts 
Quote:
Any that are over 1999 unfactored; under 50,000,000 and not assigned to anyone else are the best choices for this project. Thanks for your help. 

20210130, 01:43  #337 
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
1000111001011_{2} Posts 
Is there an easy way to look for TF candidates....
Not sure if this is the right place to ask where those who know will see it and answer.
Anyway, as most are aware in this subproject I am factoring to get 100K ranges under 2000 unfactored. Yes, I know I am already well below the DC wavefront and some see no benefit it this work but alas I proceed. As I understand it, (correct me if I'm wrong), once a PRP(xx??) test is done and verified/certified it can indicate if the remaining factor is a ProbablePrime. I take this to mean it is a waste of time (or a bigger waste of time) to bother looking for factors of these exponents. Am I making sense? Anyway, if I am on the right track then I would like to know if there is an easy way to select a list of exponents to factor (TF or P1 or ECM) that are NOT PRP. Thanks. 
20210130, 01:56  #338 
Apr 2010
Over the rainbow
2·5·11·23 Posts 
the line is
PRPDC=N/A,1,2,10014791,1,99,0,3,5,"50474546641" and will most likelly end with a 'not prime' 10M seem to be the wavefront for cofactor checking. And each check at that range take me around 1H30 min Last fiddled with by firejuggler on 20210130 at 02:00 
20210130, 02:10  #339  
Jun 2003
4,861 Posts 
Quote:


20210130, 02:58  #340  
"James Heinrich"
May 2004
exNorthern Ontario
CC7_{16} Posts 
Quote:
All the other exponents (almost?) certainly have factors waiting to be discovered. 

20210130, 03:45  #341 
Jul 2003
wear a mask
1,553 Posts 
If an exponent does not correspond to a Mersenne prime, then that exponent corresponds to a composite Mersenne number. If it's composite, it has a factor.
When a factor, f, is found for a Mersenne number, Mp = 2^p1, we can check if the cofactor, (2^p1)/f is a probable prime. The PRPcofactor effort is the search for these large PRP cofactors. That search has essentially two stages: 1) Find a factor for a composite Mp and 2) Test the cofactor for probableprimality. If stage 2 has a negative result (not PRP), repeat steps 1) and 2) to find the next factor, cofactor pair. The under2000 search is helping the PRPcofactor effort by finding the first factor for A LOT of known composite Mersenne numbers. Does that make sense? 
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