20041229, 15:06  #1 
Aug 2002
2^{3}·1,051 Posts 
M815...
Our starting point...

20041229, 15:41  #2 
Aug 2002
2^{3}·1,051 Posts 
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:
GMPECM 5.0.3 [powered by GMP 4.1.4] [ECM] Input number is 218497496936607064853048583478354175496839440705647678599864575975883972208808167719614290358159090999064327310325620422930884252602183354953346451122776638950446123565515229051718149272758321962318725648740732173736042431692028683588857933856767 (246 digits) Using special division for factor of 2^8151 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 GMPECM 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 2^8151 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 GMPECM 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 2^8151 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 
20041229, 15:55  #3 
Aug 2002
2^{3}·1,051 Posts 
I tried to verify all the factors and I ended up with:
31 * 704161 * 150287 * 110211473 * 27669118297 * 36230454570129675721 
20041229, 17:57  #4 
Jun 2003
2·59 Posts 
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 
20041229, 18:24  #5  
Oct 2004
tropical Massachusetts
105_{8} Posts 
Quote:
2^{163}1 = 704161 * 150287 * 110211473 * 27669118297 * 36230454570129675721 

20041229, 18:35  #6  
"Sander"
Oct 2002
52.345322,5.52471
4A5_{16} Posts 
Quote:


20041229, 20:52  #7 
Aug 2002
2^{3}·1,051 Posts 
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? 
20041229, 22:42  #8  
"Sander"
Oct 2002
52.345322,5.52471
29·41 Posts 
Quote:


20041229, 23:32  #9  
Aug 2002
20330_{8} Posts 
Quote:


20041230, 07:39  #10  
"Sander"
Oct 2002
52.345322,5.52471
29·41 Posts 
Quote:
Last fiddled with by smh on 20041230 at 07:39 

20041230, 14:33  #11  
Aug 2002
2^{3}×1,051 Posts 
Quote:
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? 
