Found a factor? Post it here. - Page 128

GP2 · 2019-04-14, 10:46

Quote:

Originally Posted by lycorn

Yes, I agree. But my point has to do with the way the factors were reported.

He is probably using GMP-ECM for stage 2. That would be the logical thing to do for such small exponents. And in that case there would be no automatic reporting to Primenet.

Quote:

This reminds that when a factor was eventually found for M1061, a couple of years ago, F-ECM showed up in the report, although other method had been used. I think it was SNFS.

But for M1061 it was split into two primes of 143 digits and 177 digits. With NFS you usually get enormous factors and the exponent ends up fully factored, and it's usually only feasible for the Cunningham ranges, in the low 1K exponent values. These factors and these exponents from Ryan Propper don't match that at all. They are much more typical of deep ECM.

newalex · 2019-04-14, 11:15

Maybe he uses GMP-ECM and doesn't want to email results without factors? And uses a lot of computing power to compete 55-60 digits range for one exponent in few days.

I believe the problem with curves and bounds is the problem of version 29.6 which I am using. Perhaps it submits results in JSON format which is not parsed correctly by server. Text results in results.txt look identical to previous versions.

By the way I found another 40+ digits factor with 30 digits bounds. I am curious what is probability of such discovery?

[Sun Apr 14 07:19:46 2019]
ECM found a factor in curve #147, stage #2
Sigma=7835381084152872, B1=250000, B2=25000000.
M389749 has a factor: 35157083141838820140048845608443589051481 (ECM curve 147, B1=250000, B2=25000000)
134.69 bits

lycorn · 2019-04-14, 13:36

Quote:

Originally Posted by GP2

He is probably using GMP-ECM for stage 2. That would be the logical thing to do for such small exponents. And in that case there would be no automatic reporting to Primenet.

That makes sense. It was probably the case. It is just a pity the whole amount of curves done wasn"t reported.

Thecmaster · 2019-04-14, 21:02

woooohooooooo First P-1 factor

Factor: 73683712459653894665954956209427783 / (P-1, B1=695000, B2=13205000, E=12)

petrw1 · 2019-04-14, 22:06

Beyond good luck...

lycorn · 2019-04-14, 22:53

Indeed. The default value (2500) for the ecm progress table will soon have to be raised or the table will display no values at all...

SethTro · 2019-04-15, 04:32

This was the 6th smallest M without a factor!
https://www.mersenne.org/report_ecm/
https://www.mersenne.ca/exponent/2377

187 bits! and impossible to find with P-1 go ECM

Jwb52z · 2019-04-17, 15:16

P-1 found a factor in stage #1, B1=695000.
UID: Jwb52z/Clay, M91216309 has a factor: 646532530928667932245369 (P-1, B1=695000)

79.097 bits

retina · 2019-04-17, 15:43

Quote:

Originally Posted by SethTro

This was the 6th smallest M without a factor!
https://www.mersenne.org/report_ecm/
https://www.mersenne.ca/exponent/2377

187 bits! and impossible to find with P-1 go ECM

Already reported just 10 posts before yours.

Jwb52z · 2019-04-19, 13:39

P-1 found a factor in stage #1, B1=695000.
UID: Jwb52z/Clay, M91221769 has a factor: 4115254730949418739220409 (P-1, B1=695000)

81.767 bits

Thecmaster · 2019-04-20, 18:40

90901697 F-PM1 2019-04-20 17:20 0.0 Factor: 462195198223850274269081 / (P-1, B1=695000)

Where and how can you check bitlevel on a factor?

2019-04-14, 22:06	#1402
petrw1 1976 Toyota Corona years forever! "Wayne" Nov 2006 Saskatchewan, Canada 5²×211 Posts	2477 makes 4 for Ryan Beyond good luck...

2019-04-15, 04:32	#1404
SethTro "Seth" Apr 2019 3²×53 Posts	M2377 just had a factor found This was the 6th smallest M without a factor! https://www.mersenne.org/report_ecm/ https://www.mersenne.ca/exponent/2377 187 bits! and impossible to find with P-1 go ECM

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2019-04-14, 11:15	#1399
newalex Feb 2019 10₁₆ Posts	Maybe he uses GMP-ECM and doesn't want to email results without factors? And uses a lot of computing power to compete 55-60 digits range for one exponent in few days. I believe the problem with curves and bounds is the problem of version 29.6 which I am using. Perhaps it submits results in JSON format which is not parsed correctly by server. Text results in results.txt look identical to previous versions. By the way I found another 40+ digits factor with 30 digits bounds. I am curious what is probability of such discovery? [Sun Apr 14 07:19:46 2019] ECM found a factor in curve #147, stage #2 Sigma=7835381084152872, B1=250000, B2=25000000. M389749 has a factor: 35157083141838820140048845608443589051481 (ECM curve 147, B1=250000, B2=25000000) 134.69 bits

2019-04-14, 21:02	#1401
Thecmaster "Arvid Björklin" Apr 2016 Pitea, Sweden 106₈ Posts	woooohooooooo First P-1 factor Factor: 73683712459653894665954956209427783 / (P-1, B1=695000, B2=13205000, E=12)

2019-04-14, 22:53	#1403
lycorn "GIMFS" Sep 2002 Oeiras, Portugal 3042₈ Posts	Indeed. The default value (2500) for the ecm progress table will soon have to be raised or the table will display no values at all...

2019-04-17, 15:16	#1405
Jwb52z Sep 2002 5·13² Posts	P-1 found a factor in stage #1, B1=695000. UID: Jwb52z/Clay, M91216309 has a factor: 646532530928667932245369 (P-1, B1=695000) 79.097 bits

2019-04-19, 13:39	#1407
Jwb52z Sep 2002 5×13² Posts	P-1 found a factor in stage #1, B1=695000. UID: Jwb52z/Clay, M91221769 has a factor: 4115254730949418739220409 (P-1, B1=695000) 81.767 bits

2019-04-20, 18:40	#1408
Thecmaster "Arvid Björklin" Apr 2016 Pitea, Sweden 70₁₀ Posts	90901697 F-PM1 2019-04-20 17:20 0.0 Factor: 462195198223850274269081 / (P-1, B1=695000) Where and how can you check bitlevel on a factor?