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Old 2011-06-03, 09:06   #45
lorgix
 
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It'd be nice if it did work. I think that's how the reasoning goes, rather than going for maximum efficiency.

How would you define a modest effort?

Your paper isn't available online, is it? Other than here, $24.
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Old 2011-06-03, 10:25   #46
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Math. Comp. papers more than five years old are all available for free now. The complete list for Bob is here
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Old 2011-06-04, 14:42   #47
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Interesting read, thanks.
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Old 2011-06-17, 08:02   #48
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Reporting a few curves:

100*11e7
200*26e7
100*85e7
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Old 2011-06-17, 16:10   #49
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Quote:
Originally Posted by jasonp View Post
Math. Comp. papers more than five years old are all available for free now. The complete list for Bob is here
I've read the papers by Robert D Silverman. I assume Joseph H Silverman is a different person.

Chris K
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Old 2012-07-07, 22:16   #50
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I completed 1000 curves at B1=85e7
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Old 2012-07-25, 12:05   #51
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Quote:
Originally Posted by ATH View Post
I did 3x P+1 curves with B1=232-1 and B2=1015, no factor.
I redid 3 x P+1 curves since GMP-ECM now can take B1 above 232-1.

I did B1=1.2*1011 and B2=3.2*1016, but still no factor.
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Old 2012-09-11, 16:12   #52
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Default EM47 factored

Hello,

I'm pleased to report that after about a month of parallel computation on several machines, I factored the c256 that's the next roadblock in the Euclid-Mullin sequence, using GMP-ECM with B1=85e7:

Code:
GMP-ECM 6.4.2 [configured with GMP 4.2.1, --enable-asm-redc] [ECM]
Input number is 1103211021556224950320857474629136274403207171149379589714114723150386622499653804938278785515108572580176773848180740319473132010224746780126854078078147700083327285484886146503985210746878713815121432016326226877964286156464913770459306370172713035675031 (256 digits)
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=48290507
Step 1 took 5722249ms
Step 2 took 890944ms
Run 2 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=2368313139
Step 1 took 5759385ms
Step 2 took 884748ms
Run 3 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=3904025998
Step 1 took 5661024ms
Step 2 took 888516ms
Run 4 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=3337981105
Step 1 took 5658077ms
Step 2 took 866615ms
Run 5 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=677133381
Step 1 took 5561290ms
Step 2 took 865897ms
Run 6 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=102243527
Step 1 took 5638946ms
Step 2 took 864061ms
Run 7 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=1174820872
Step 1 took 5712777ms
Step 2 took 874411ms
Run 8 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=3792471659
Step 1 took 5547897ms
Step 2 took 868668ms
Run 9 out of 10:
Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=2224648366
Step 1 took 5556475ms
Step 2 took 865855ms
********** Factor found in step 2: 227432689108589532754984915075774848386671439568260420754414940780761245893
Found probable prime factor of 75 digits: 227432689108589532754984915075774848386671439568260420754414940780761245893
Probable prime cofactor 4850714406447914527347493347887006780765353433979065623675486187490387777411140183141044936823311325371603159045427508919677245335424955781302624439588917360053192836163350828151467 has 181 digits
Report your potential champion to Richard Brent <champs@rpbrent.com>
(see http://wwwmaths.anu.edu.au/~brent/ftp/champs.txt)
This leads immediately to a few more terms in the sequence:

227432689108589532754984915075774848386671439568260420754414940780761245893
59
31
211

Haven't tried attacking the next one yet. :)

Cheers,

Ryan Propper
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Old 2012-09-11, 18:05   #53
ATH
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Very nice work! Imagine HP49(110) and EM47 factored within a few days.

Correct me if I'm wrong, but the next EM51 number to factor is this 335 digit?

Code:
96829488818499592481168771836336683023181156945795350980834458372199490598743221067775290195641203125439681639536219726888871822435629511515837059837171813128663335953886175536897367740550240372528813404899458874513057418332695709006061299277468749241875966062032012477732299909160292749026996368849279816035027111164073836173908645011
No factor up to 25 digits.
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Old 2012-09-11, 18:10   #54
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Yep, that looks to be the next roadblock... a c335 seems pretty challenging. I'm sure we'll give it a shot, though :)
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Old 2012-09-11, 18:26   #55
ATH
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I'm wondering why you use a GMP-ECM built on the old GMP 4.2.1. I'm sure the new GMP 5.0.5 is a little faster but if you use 64bit GMP-ECM then MPIR is even faster.

Here is my old GMP 5.0.2 vs MPIR 2.4.0 tests: core2-64bittests.html which showed MPIR up to 40-50% faster.

I haven't tested the new GMP 5.0.5 vs MPIR 2.5.1 but in all 64bit testing I never found GMP faster than MPIR. But in 32bit GMP was 10-15% faster than MPIR: core2-32bittests.html
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