Thinking out loud about getting under 20M unfactored exponents - Page 31

petrw1 · 2021-01-04, 01:14

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 P-1, 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.

Result does show up in my results at 18:32

Prime95 · 2021-01-04, 02:37

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.

firejuggler · 2021-01-08, 13:02

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]
P-1 found a factor in stage #2, B1=1350000, B2=89100000.
UID: firejuggler/Maison, M27152453 has a factor: 214211625581311913643047 (P-1, B1=1350000, B2=89100000)
[Fri Jan  8 05:29:00 2021]
P-1 found a factor in stage #1, B1=1350000.
UID: firejuggler/Maison, M27153151 has a factor: 4694191350737025517407343 (P-1, B1=1350000)
[Fri Jan  8 06:41:42 2021]
P-1 found a factor in stage #1, B1=1350000.
UID: firejuggler/Maison, M27153359 has a factor: 26637694127747536479168769 (P-1, B1=1350000)

3 factors found, on the same computer, on the same night.

petrw1 · 2021-01-08, 15:13

Quote:

Originally Posted by firejuggler

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]
P-1 found a factor in stage #2, B1=1350000, B2=89100000.
UID: firejuggler/Maison, M27152453 has a factor: 214211625581311913643047 (P-1, B1=1350000, B2=89100000)
[Fri Jan  8 05:29:00 2021]
P-1 found a factor in stage #1, B1=1350000.
UID: firejuggler/Maison, M27153151 has a factor: 4694191350737025517407343 (P-1, B1=1350000)
[Fri Jan  8 06:41:42 2021]
P-1 found a factor in stage #1, B1=1350000.
UID: firejuggler/Maison, M27153359 has a factor: 26637694127747536479168769 (P-1, B1=1350000)

3 factors found, on the same computer, on the same night.

seatsea · 2021-01-12, 20:07

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 0.15pre7-MGW cl_barrett15_71_gs_2]
tf(): total time spent:  2m  8.875s (1880.09 GHz-days / day)

petrw1 · 2021-01-12, 23:30

Quote:

Originally Posted by seatsea

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 0.15pre7-MGW cl_barrett15_71_gs_2]
tf(): total time spent:  2m  8.875s (1880.09 GHz-days / day)

Yes that's a good range.
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.

petrw1 · 2021-01-30, 01:43

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 sub-project 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 Probable-Prime.
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.

firejuggler · 2021-01-30, 01:56

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

axn · 2021-01-30, 02:10

Quote:

Originally Posted by petrw1

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 Probable-Prime.
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?

I am not sure I understand you correctly. Could you explain further with an example?

James Heinrich · 2021-01-30, 02:58

Quote:

Originally Posted by petrw1

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.

There are 350 exponents that are fully-factored (where the last factor is either certainly or probably prime).
All the other exponents (almost?) certainly have factors waiting to be discovered.

masser · 2021-01-30, 03:45

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^p-1, we can check if the cofactor, (2^p-1)/f is a probable prime. The PRP-cofactor 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 probable-primality. If stage 2 has a negative result (not PRP), repeat steps 1) and 2) to find the next factor, cofactor pair.

The under-2000 search is helping the PRP-cofactor effort by finding the first factor for A LOT of known composite Mersenne numbers.

Does that make sense?

2021-01-12, 20:07	#335
seatsea Jan 2021 2₁₀ 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 0.15pre7-MGW cl_barrett15_71_gs_2] tf(): total time spent: 2m 8.875s (1880.09 GHz-days / day)

2021-01-30, 01:43	#337
petrw1 1976 Toyota Corona years forever! "Wayne" Nov 2006 Saskatchewan, Canada 2²·17·67 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 sub-project 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 Probable-Prime. 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.

2021-01-30, 01:56	#338
firejuggler 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 Attached Thumbnails Last fiddled with by firejuggler on 2021-01-30 at 02:00

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2021-01-04, 02:37	#332
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 2²·7·263 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.

2021-01-30, 03:45	#341
masser Jul 2003 wear a mask 3021₈ 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^p-1, we can check if the cofactor, (2^p-1)/f is a probable prime. The PRP-cofactor 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 probable-primality. If stage 2 has a negative result (not PRP), repeat steps 1) and 2) to find the next factor, cofactor pair. The under-2000 search is helping the PRP-cofactor effort by finding the first factor for A LOT of known composite Mersenne numbers. Does that make sense?