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Old 2004-12-29, 15:06   #1
Xyzzy
 
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Default M815...

Our starting point...
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Old 2004-12-29, 15:41   #2
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I'm assuming that these have been found before... I'm not sure how to read this table yet...

http://www.cerias.purdue.edu/homes/ssw/cun/pmain1104

Code:
815  (5,163)                                                            C195
Code:
GMP-ECM 5.0.3 [powered by GMP 4.1.4] [ECM]
Input number is 218497496936607064853048583478354175496839440705647678599864575975883972208808167719614290358159090999064327310325620422930884252602183354953346451122776638950446123565515229051718149272758321962318725648740732173736042431692028683588857933856767 (246 digits)
Using special division for factor of 2^815-1
Using B1=11000000, B2=25577181640, polynomial Dickson(12), sigma=310509380
Step 1 took 147943ms
********** Factor found in step 1: 361561253939446794241
Found composite factor of 21 digits: 361561253939446794241
Composite cofactor 604316680938384999564988132158021631808471405730103444409194082133448180970187699144517112304593965085487053762394518119842162636283587094959484733832833176883618784094798608264390757867707841826049167028642161062069913765887 has 225 digits

GMP-ECM 5.0.3 [powered by GMP 4.1.4] [ECM]
Input number is 604316680938384999564988132158021631808471405730103444409194082133448180970187699144517112304593965085487053762394518119842162636283587094959484733832833176883618784094798608264390757867707841826049167028642161062069913765887 (225 digits)
Run 2 out of 30:
Using special division for factor of 2^815-1
Using B1=2000, B2=119805, polynomial x^1, sigma=1907432544
a=111646706479743411117763961374133163161644655905812697324957514626176959224844266240214215481598924628248550290444134136311097173050792284325829402090282080563262191821873379081464849522330932356057017626575310476560981846274
starting point: x=151725799614516533738654453507210545525911773563761176885961901870360669320127287302484168052955540704624299033265802972938701571229585476644088680901102126512430358526672332081130758813370088379934959969032237321836718344288
Step 1 took 28ms
********** Factor found in step 1: 27669118297
Found probable prime factor of 11 digits: 27669118297
Composite cofactor 21840836215005358815860937954268114342887310173478327819706096872359191567996775446527598193982811503879235944935485203178614413810917507132572318187332703385984543434213884530141764996470203274076130458080789384471 has 215 digits

GMP-ECM 5.0.3 [powered by GMP 4.1.4] [ECM]
Input number is 21840836215005358815860937954268114342887310173478327819706096872359191567996775446527598193982811503879235944935485203178614413810917507132572318187332703385984543434213884530141764996470203274076130458080789384471 (215 digits)
Run 63 out of 90:
Using special division for factor of 2^815-1
Using B1=11000, B2=1359460, polynomial x^1, sigma=2350230673
a=16609114659953808045481590026023283899137046335604314390770135251973527796604431928479668961956394621483475403158526566939304459078316960439175405174650538660993640395191584906221057599686103195418792014977916415723
starting point: x=18671191872994448206642461501291893452034142385606704580512784137034632633141951017335416725481092984654231375793118520700323552427059842603524908138169578321922738300713660813707093741585664898932000210358447215107
Step 1 took 157ms
x=11548375251574425308481485624033761117089551610339017020738194578795856125104449350593025749010297141567516431239189947256172512781279313508847546678699126968611627734956660102159358501424737390656464443574560041187
B2'=1612800 k=5 b2=320880 d=1680 dF=192
Initializing table of differences for F took 1ms
Computing roots of F took 12ms and 1674 muls
Building F from its roots took 6ms and 2517 muls
Computing 1/F took 6ms and 3500 muls
Initializing table of differences for G took 1ms
Computing roots of G took 8ms and 1152 muls
Building G from its roots took 5ms and 2517 muls
Computing roots of G took 8ms and 1152 muls
Building G from its roots took 5ms and 2517 muls
Computing G * H took 5ms and 1715 muls
Reducing G * H mod F took 8ms and 3427 muls
Computing roots of G took 8ms and 1152 muls
Building G from its roots took 7ms and 2517 muls
Computing G * H took 4ms and 1715 muls
Reducing G * H mod F took 8ms and 3427 muls
Computing roots of G took 7ms and 1152 muls
Building G from its roots took 6ms and 2517 muls
Computing G * H took 5ms and 1715 muls
Reducing G * H mod F took 8ms and 3427 muls
Computing roots of G took 9ms and 1152 muls
Building G from its roots took 5ms and 2517 muls
Computing G * H took 6ms and 1715 muls
Reducing G * H mod F took 9ms and 3427 muls
Computing polyeval(F,G) took 25ms and 11828 muls
Step 2 took 172ms for 58432 muls
********** Factor found in step 2: 36230454570129675721
Found probable prime factor of 20 digits: 36230454570129675721
Composite cofactor 602830863541306826308201254740270750540731095667474187448714011010899950408657957299250392174354769529862228623065037288911156431857765333506478693299526142358853365961098168445571416785159158751 has 195 digits
From here, do we work on the c195 or the original number?
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Old 2004-12-29, 15:55   #3
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I tried to verify all the factors and I ended up with:

31 * 704161 * 150287 * 110211473 * 27669118297 * 36230454570129675721
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Old 2004-12-29, 17:57   #4
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For factors of mersenne numbers I use

ftp://mersenne.org/gimps/lowm.txt

which has all known factors for <M(10000) listed in a nice readable format:

M( 815 )C: 31
M( 815 )C: 150287
M( 815 )C: 704161
M( 815 )C: 110211473
M( 815 )C: 27669118297
M( 815 )C: 36230454570129675721

Thomas
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Old 2004-12-29, 18:24   #5
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Quote:
Originally Posted by Xyzzy
I tried to verify all the factors and I ended up with:

31 * 704161 * 150287 * 110211473 * 27669118297 * 36230454570129675721
25-1 = 31
2163-1 = 704161 * 150287 * 110211473 * 27669118297 * 36230454570129675721
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Old 2004-12-29, 18:35   #6
smh
 
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Quote:
From here, do we work on the c195 or the original number?
Depends on which is faster. For GMP-ECM the c195 probably is. Don't know if running prime95 is faster running the full number.
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Old 2004-12-29, 20:52   #7
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Thanks for all the tips!

I'll have c195 done through 35 digits later tonight and I'll start on 40 digits then...

How do we coordinate work if some people are doing the whole number and some are doing the c195 part?
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Old 2004-12-29, 22:42   #8
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Quote:
Originally Posted by Xyzzy
Thanks for all the tips!

I'll have c195 done through 35 digits later tonight and I'll start on 40 digits then...

How do we coordinate work if some people are doing the whole number and some are doing the c195 part?
Why doing the 35 and 40 digit level again? Enough curves have been ran to be fairly certain no factors below 40 digits exist
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Old 2004-12-29, 23:32   #9
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Quote:
Originally Posted by smh
Why doing the 35 and 40 digit level again? Enough curves have been ran to be fairly certain no factors below 40 digits exist
Hmm... I guess because I don't know where to start...

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Old 2004-12-30, 07:39   #10
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Quote:
Originally Posted by Xyzzy
Hmm... I guess because I don't know where to start...

But you gave the table of ECM curves done youreself in the first post of this thread

Last fiddled with by smh on 2004-12-30 at 07:39
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Old 2004-12-30, 14:33   #11
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Quote:
Originally Posted by smh
But you gave the table of ECM curves done youreself in the first post of this thread
I guess I wasn't thinking straight... If the base number has been done to a certain depth that must mean the subparts have also been done to that depth...

I guess I'll start on the 50 digit depth... Does anybody know how much a curve at 50 on the c195 is worth compared to a curve at 50 on the base number? Or is it the same?
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