20110604, 14:42  #47 
Sep 2010
Scandinavia
3×5×41 Posts 
Interesting read, thanks.

20110617, 08:02  #48 
Sep 2010
Scandinavia
3×5×41 Posts 
Reporting a few curves:
100*11e7 200*26e7 100*85e7 
20120707, 22:16  #50 
Nov 2009
2×5^{2}×7 Posts 
I completed 1000 curves at B1=85e7

20120725, 12:05  #51 
Einyen
Dec 2003
Denmark
3×13×71 Posts 

20120911, 16:12  #52 
Jun 2012
Boulder, CO
9D_{16} Posts 
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 EuclidMullin sequence, using GMPECM with B1=85e7: Code:
GMPECM 6.4.2 [configured with GMP 4.2.1, enableasmredc] [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) 227432689108589532754984915075774848386671439568260420754414940780761245893 59 31 211 Haven't tried attacking the next one yet. :) Cheers, Ryan Propper 
20120911, 18:05  #53 
Einyen
Dec 2003
Denmark
3·13·71 Posts 
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 
20120911, 18:10  #54 
Jun 2012
Boulder, CO
157_{10} Posts 
Yep, that looks to be the next roadblock... a c335 seems pretty challenging. I'm sure we'll give it a shot, though :)

20120911, 18:26  #55 
Einyen
Dec 2003
Denmark
3·13·71 Posts 
I'm wondering why you use a GMPECM 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 GMPECM then MPIR is even faster.
Here is my old GMP 5.0.2 vs MPIR 2.4.0 tests: core264bittests.html which showed MPIR up to 4050% 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 1015% faster than MPIR: core232bittests.html 