Small n factoring

[vjs]

I noticed a few people are now doing small n factoring...

I was wondering if anyone was going to keep track or how we should keep track.

If anyone does decide to do this type of factoring I suggest you use very very large bounds. Or certainly you work will be repeated.

The hardest pair to crack right now is k=24737 n=991

It's been ecm'ed to 1800+ curves, p-1 to very deep B1=B2=(??24G??), very limited P+1.

[Joe O]

Actually ECM for 40 digits has been completed

[Sun Feb 20 18:08:42 2005]
24737*2^991+1 completed 5100 ECM curves, B1=3000000, B2=640000000

and ECM for 45 digits has been started.

Mystwalker posted in the Mersenne forum:

I have done 100 curves with B1=11M (using Prime95) - stage1 only, so far.

Before putting gmp-ecm on stage2, I will wait until version 6 comes out, which is said to be faster especially in stage2.

and I've done a dozen or so curves myself.

[Mystwalker]

Currently, I run ECM curves for 25 (and started 30 digits on some where no factor was found) on all numbers with n < 2000.
So far, I found 7 or 8 factors, 13 numbers[1] are left.

Current status:

digits:		25	30

21181,1148	ok	ok
21181,1172	ok	ok
10223,1181	ok	
21181,1268	ok	
27653,1257	ok	
33661,1320	ok	
10223,1517	ok	
10223,1529	ok	
24737,1543	ok	
24737,1567	ok	
55459,1666	ok	ok
55459,1894	ok	ok
55459,1966	ok	ok

If somebody wants to do work here, I'd propose the 30 digit range (B1=250k, 700 curves with B2=100*B1) for those numbers that are already tested upto 25 digits. As the 25 digit range takes roughly 30 minutes for my Duron, there should be enough 30 digit work for everyone.
Please state when you do some work.

Note: "res" = reserved

I'd advise using Prime95/mprime ver. 24.6, which can fastly do ECM curves on these kind of numbers. The syntax is:

ECM2=21181,2,1148,1,250000,25000000,700

for 700 curves with B1=250000 and B2=25000000 on 21181*2^1148.
On Pentium-M machines, turning off SSE2 can speed up computation.

I was inspired when I saw the list on the MikeH's stats pages - and now noticed that this has been recently added, just like the new features from today/yesterday.

For 24737*2^991+1, I already have ~400 curves of the 45 digit level at stage1. Stage2 with B2=100*B1 takes approx. 1 minute, but with the improved performance of gmp-ecm6 and the feature to see how many curves are needed, I gonna find a more optimal B2 value...

[1]I just noticed that some new numbers have been added as unfactored.

[MikeH]

[1]I just noticed that some new numbers have been added as unfactored.

Which ones? I've probably messed something up...

As a separate exercise I'll look at doing a 'low n' sob.dat so anyone that wants to join the party can do so relatively easily.

BTW, anyone that finds any factors that are too big to submit in the usual way, just send them to me (and post them here if you like), and let me know the SoB user id you'd like them credited to. Thx.

[Mystwalker]

Assuming I didn't oversee them, the following have appeared after I initially made up the worktodo file:

21181*2^1172+1
21181*2^1268+1
19249*2^1346+1
24737*2^1543+1
24737*2^1567+1
21181*2^1772+1

For these numbers, it would be no big deal, as my testing would find factors very quickly when factors have already been found. After all, sieving is at ~15 digits, whereas I test for 25 digits...
It could be a problem when other (bigger) numbers are affected as well, though.

edit:
605094683116556462184679 | 19249*2^1346+1

It took almost 200 curves, so I guess there is no smaller factor. This one seems to be legitimate...

21181*2^1172+1 and 21181*2^1268+1 most likely don't have a factor < 25 digits.

btw.:
One entry seems to be false:

10223       509      Mon 21-Feb-2005    Mystwalker

I'm pretty sure I didn't test this lately. Maybe it's a lot older?

[MikeH]

21181*2^1172+1
21181*2^1268+1
19249*2^1346+1
24737*2^1543+1
24737*2^1567+1
21181*2^1772+1

Just been back through my backups, and these have been there on every page (or at least the 03:00 versions, since that's the only ones I keep) since I first started showing this data (22 Feb).

One entry seems to be false:

I agree, it's much older. This is date when I finally incorporated it into my database. Better late than never.

[Mystwalker]

Originally posted by MikeH
Just been back through my backups, and these have been there on every page (or at least the 03:00 versions, since that's the only ones I keep) since I first started showing this data (22 Feb).

Hm, ok. Must have been my mistake. Never mind...

I agree, it's much older. This is date when I finally incorporated it into my database. Better late than never.

In addition, I can't remember that I've found a 38 digit factor. It doesn't look like a P-1 factor to me...

As a separate exercise I'll look at doing a 'low n' sob.dat so anyone that wants to join the party can do so relatively easily.

I think you can start with n=2016, as it is highly unlikely that sieving will ever get to 25 digits...

All in all, maybe it's even completely unwise to sieve these low n's - depending on the amount of numbers. It should take only a few seconds per number to test them upto 15 digits with ECM. Maybe a minute or two for 20 digits. So, the top100 for each k can be tested to 20 digits in 33 hours.

These figures are for a 850 MHz system...

edit:
I forgot to consider that ECM curves take longer for higher n's. It would thus take more time - I don't no how much longer, though...

[Joe O]

Originally posted by Mystwalker


My factorer gave me this:

Using B1=3000000, B2=4016636514, polynomial Dickson(12), sigma=1948938696
Step 1 took 150878ms
Step 2 took 105525ms
********** Factor found in step 2: 21133297510706620304719126766866230127
Found probable prime factor of 38 digits: 21133297510706620304719126766866230127
Probable prime cofactor  81073493380742712605879137929073445260114635803005
 03681635553856576597751904480764074787326160157437
20104914903574795151 has 120 digits

I tried to factor 10223*2^509+1 - can someone verify this result?
The sieve submission pages don't work for n<1000...


I almost wiped out this factor, as I was almost in the act of powering down the computer. Thought the program did "I don't know what" cuz it has been terminated too early. Well, now I know why...

Mystwalker,
Check the 11th post and following in this thread.

So it's not a false entry, you really did factor this k n pair. I captured the information and sent it to Mike.

[Joe O]

I did this back in September:

sbfactor12.55.exe 24737 991 sbECM25.cfg
sbfactor12.55.exe 21181 1148 sbECM25.cfg
sbfactor12.55.exe 19249 1166 sbECM25.cfg
;sbfactor12.55.exe 21181 1172 sbECM25.cfg
sbfactor12.55.exe 10223 1181 sbECM25.cfg
sbfactor12.55.exe 27653 1257 sbECM25.cfg
;sbfactor12.55.exe 21181 1268 sbECM25.cfg
sbfactor12.55.exe 55459 1306 sbECM25.cfg
sbfactor12.55.exe 33661 1320 sbECM25.cfg
;sbfactor12.55.exe 19249 1346 sbECM25.cfg
;sbfactor12.55.exe 24737 1471 sbECM25.cfg
Pause
sbfactor12.55.exe 55459 1498 sbECM25.cfg
sbfactor12.55.exe 10223 1517 sbECM25.cfg
sbfactor12.55.exe 10223 1529 sbECM25.cfg
sbfactor12.55.exe 24737 1543 sbECM25.cfg
sbfactor12.55.exe 24737 1567 sbECM25.cfg
sbfactor12.55.exe 33661 1608 sbECM25.cfg
sbfactor12.55.exe 55459 1666 sbECM25.cfg
sbfactor12.55.exe 21181 1772 sbECM25.cfg
sbfactor12.55.exe 55459 1894 sbECM25.cfg
sbfactor12.55.exe 55459 1966 sbECM25.cfg
sbfactor12.55.exe 33661 2016 sbECM25.cfg
Pause
sbfactor12.55.exe 67607 2051 sbECM25.cfg
sbfactor12.55.exe 24737 2071 sbECM25.cfg
sbfactor12.55.exe 55459 2134 sbECM25.cfg
sbfactor12.55.exe 19249 2138 sbECM25.cfg
sbfactor12.55.exe 24737 2191 sbECM25.cfg
sbfactor12.55.exe 4847 2247 sbECM25.cfg
sbfactor12.55.exe 55459 2290 sbECM25.cfg
sbfactor12.55.exe 67607 2411 sbECM25.cfg
sbfactor12.55.exe 28433 2473 sbECM25.cfg
sbfactor12.55.exe 10223 2537 sbECM25.cfg
sbfactor12.55.exe 22699 2638 sbECM25.cfg
Pause
sbfactor12.55.exe 55459 2674 sbECM25.cfg
sbfactor12.55.exe 55459 2686 sbECM25.cfg
sbfactor12.55.exe 4847 2751 sbECM25.cfg
sbfactor12.55.exe 10223 2789 sbECM25.cfg
sbfactor12.55.exe 33661 2808 sbECM25.cfg
sbfactor12.55.exe 4847 2847 sbECM25.cfg
sbfactor12.55.exe 24737 2863 sbECM25.cfg
sbfactor12.55.exe 27653 2877 sbECM25.cfg
sbfactor12.55.exe 27653 2913 sbECM25.cfg
sbfactor12.55.exe 27653 2985 sbECM25.cfg
sbfactor12.55.exe 22699 2998 sbECM25.cfg

And sbECM25.cfg has

# or using manual bounds
bounds = manual
B1 = 50000
B2 = 15000000

# only relevant for ECM
curves = 400

So all n less than 3000 have had enough ECM done on them to find 25 digit factors.

You'll notice that there are 4 numbers with semicolons on the line. I skipped these because I had reason to believe that they were already factored. I'll have to check my notes to see why I thought that. One of them Mystwalker just factored.

EDIT:
Turns out I did find in sbfactor.log that I had also run ECM on those 4 k n pairs, Yet did not find a factor. ECM is a probabalistic algorithm, so success is not guarraneed. So more work on these k n pairs may be justified. But use Prime95 as Mystwalker suggests.
Oh yes, I had also run
bounds = manual
B1 = 2000
B2 = 600000

# only relevant for ECM
curves = 40

and

bounds = manual
B1 = 11000
B2 = 2000000

# only relevant for ECM
curves = 120

on all these k n pairs.

[Mystwalker]

Originally posted by Joe O
Mystwalker,
Check the 11th post and following in this thread.

So it's not a false entry, you really did factor this k n pair. I captured the information and sent it to Mike.

Ah, ok. I just couldn't remember. Thanks!

So all n less than 3000 have had enough ECM done on them to find 25 digit factors.

You'll notice that there are 4 numbers with semicolons on the line. I skipped these because I had reason to believe that they were already factored. I'll have to check my notes to see why I thought that. One of them Mystwalker just factored.

I found some others with the 25 digits bound:

2816749407631533354401 | 19249*2^1166+1
17719414861774257915917 | 55459*2^1306+1
26783435724241223 | 24737*2^1471+1 (also excluded)
4192341180658301266763 | 33661*2^1608+1
830578932421150082798981 | 55459*2^1498+1
724805244916016081371 | 21181*2^1772+1

Of course, this is not unusual, as the chance that there is a factor of n digits left after running the appropriate curves is 1^(-e), AFAIK. So, there is a chance of something around 30% that a factor is not found so far. The levels only tell when it's optimal to switch to higher bounds...

[Joe O]

30% eh
I didn't remember that it was that high. Yes, the bounds are only the optimal point to switch to the next level. 7 out of 44, unless you found some more. Don't forget to send them to MikeH.

Oh, and the low sob.dat is not for sieving. It makes factoring easier. The select script or now the program, will create a worktodo.ini entry from the sob.dat file and results.txt file. But be careful, Prime95 uses results.txt as an output file unless you tell it to use a different name. Because Mikeh's dat files are so up to date, we probably need a script and/or program that does not need a results.txt file. This would minimize the possibility of downloading over Prime95's result file.

You know we could use a script/program to create ECM2 lines as well as PFACTOR lines.

[Joe O]

MikeH,

Instead of a "low" sob.dat file, how about 2 files?

The first would have PFACTOR lines such as:

PFACTOR=27653,2,2985,1,40.2,3.9

that people could edit as they wished before using.

The second would have ECM2 lines such as:

ECM2=24737,2,991,1,11000000,2500000000,530

that also could be edited as needed before using.

If bandwith/filespace is a problem, one file with
=27653,2,2985,1,$
=24737,2,991,1,$
would suffice. People could do global edits to put PFACTOR or ECM2 in front of the = sign and replace the $ with the other needed operands.

[MikeH]

Instead of a "low" sob.dat file, how about 2 files?

Or....how about if I update the makewtd tool so that it can generate a suitable ECM format worktodo file given a desired factor length? - i.e. it will determine suiatble B1, B2 and loops.

[Joe O]

Originally posted by MikeH
Or....how about if I update the makewtd tool so that it can generate a suitable ECM format worktodo file given a desired factor length? - i.e. it will determine suiatble B1, B2 and loops.

Even better! Thanks.

[MikeH]

A low N sob.dat especially for this low N factoring effort is available here. This is all the unfactored candidates below the double check PRP line. It'll be upated daily.

A updated version of the windows utility to create worktodo.ini files (for Prime95) is here, again with source.

Updates include:

1) Can now produce P-1 or ECM work files
2) Can pick one or more specific k

The attcahed .bat file should make it clear enough how to use, but if not, you know where to find me.

Enjoy.


BTW (just in case you lost the links): Latest versions of Prime95 can be found here, that's p95 for windows, mprime for linux.

[MikeH]

P-1 found a factor in stage #2, B1=4625000, B2=166500000.
24737*2^6631+1 has a factor: 668139145160251763062608380347404413431

39 digits, too big to submit. I've sent it to myself

Glad I did some serious P-1 in that range before moving on to ECM

[vjs]

Is anyone interested in factoring the larger numbers for the 13.6M+ account???

Since the numbers are larger it should be easier to find sooth factors...

[smh]

Originally posted by MikeH

P-1 found a factor in stage #2, B1=4625000, B2=166500000.
24737*2^6631+1 has a factor: 668139145160251763062608380347404413431

39 digits, too big to submit. I've sent it to myself

Glad I did some serious P-1 in that range before moving on to ECM

You could have factored this composite into it's prime factors, which would have made it easier to submit.

668139145160251763062608380347404413431
PRIME FACTOR 1489391276707081441
PRIME FACTOR 448598803826386770391

[MikeH]

P-1 found a factor in stage #2, B1=4060000, B2=139055000.
4847*2^8367+1 has a factor: 1110687092604384736290030992727448303

37 digits and seems to be a prime factor this time.

Thanks smh. It seems the largest three factors for low n I've submitted recently have been composite. I've been thinking about tidying up the stats pages so that somewhere we display the largest prime factors found in this project. But it's good to be aware that we do have composite factors, so I need to sort that aspect first.

[Jwb52z]

MikeH, I sympathize with your job around here because it seems like it gets increasingly tedious all the time. Of course, it may really not because it may be easier than it sounds. I don't know.

[vjs]

Mike I feel your pain about those large factors that are actually composite, it might be a good idea if everyone who finds a factor through p-1 tries factoring the factor.

This is a pretty good applet for doing so...

http://www.alpertron.com.ar/ECM.HTM

BTW nice speed on those small factors and I like the idea of the top 100 and top 10.

Is there any chance of expanding your stats further to 50M or 100M when the time comes? Would this be difficult to do etc...

[MikeH]

Is there any chance of expanding your stats further to 50M or 100M when the time comes? Would this be difficult to do etc...

Yep, that bit should be easy enough. I already use a n<50M p=1G sob.dat file, and just disable the bits above 20M that would otherwise make it a bit of a mess right now.

[Mystwalker]

I do some more ECMing on the 1k<n<2k numbers:

Current status:

digits:		25	30

21181,1148	ok	ok
21181,1172	ok	ok
10223,1181	ok	ok
21181,1268	ok	ok
27653,1257	ok	ok
33661,1320	ok	res
10223,1517	ok	res
10223,1529	ok	res
24737,1543	ok	res
24737,1567	ok	res
55459,1666	ok	ok
55459,1894	ok	ok
55459,1966	ok	ok

Note: "res" = reserved

Using gmp-ecm6 for stage2, I can lower the time for the 30 digit level from 337 to 280 minutes, a speed increase of 20%.

[vjs]

Any chance of a secret stats page for the 991<n<50M dat like the 2005 stats.

If it would be easy to do a pull from the n<50M dat it would save me time from doing it manually using excel and Joe_O's outs.

[vjs]

I posted stats on the whole 991<n<100M I'm talking about in the sieve section. It also shoulds your low n-factoring effort so I thought the factors would also like to know about them.

[Mystwalker]

Almost through with 1000 < n < 2000 for 30 digits:

		25	30					hex (hex digits)

21181,1148	ok	ok					N=0x52BD000 (292)
21181,1172	ok	ok					N=0x52BD000 (298)
10223,1181	ok	ok					N=0x4FDE000 (302)
27653,1257	ok	ok					N=0xD80A000 (319)
21181,1268	ok	ok					N=0x52BD000 (322)
33661,1320	ok	ok					N=0x837D000 (335)
10223,1517	ok	ok					N=0x4FDE000 (384)
10223,1529	ok	ok					N=0x4FDE000 (387)
24737,1543	ok	ok					N=0x3050800 (391)
24737,1567	ok	stage1 complete				N=0x3050800 (397)
55459,1666	ok	ok					N=0x3628C00 (422)
55459,1894	ok	ok					N=0x3628C00 (479)
55459,1966	ok	ok					N=0x3628C00 (497)

No new factors at that level.

I found out something strange:
As you can see at the end of each line, the numbers in hex always start the same for same k's, they only differ in the (hex) digit count.
That means that the n's of these numbers differ by a multiple of 4.
Is that

a) coincidence,
b) natural (due to some obvious implication) or
c) a phenomenon unknown so far?

[vjs]

Yes they also differ by a mulitple of 2... ?
And they exactly differ by

55459,1666
55459,1894 2^(1894-1666)
55459,1966 2^(1966-1894)

Perhaps I'm missing your point?

[Mystwalker]

Well, taken those k's, how big is the chance that each number of a k still unfactored differs by a multiple of 16 (of 2^4) to other numbers of that k?

I've just found out that the n's even all differ by a multiple of 12!
I don't think that this is just coincidence.

I *guess* that only numbers of this special form "survive" sieving by very small numbers (< 100). But I don't know, hence I'm asking...

[Joe O]

b) natural (due to some obvious implication)

Remember we are dealing with k*2^n+1

The n's for a given k are all even or all odd so they differ by an even number.

n'=n+2*j for some positive interger j

k*2^n'+1=k*2^(n+2j)+1 = k*(2^n)*(2^2J)+1=k*(2^n)*4^j+1=(4^j)*k*2^n+1

[Joe O]

Originally posted by Mystwalker

I've just found out that the n's even all differ by a multiple of 12!
I don't think that this is just coincidence.

I *guess* that only numbers of this special form "survive" sieving by very small numbers

Yes the others would be divisible by 3 or 5 or 7.

[Joe O]

Check out this thread! which contains the following:

Originally posted by wblipp This is easier to understand in table form. Here is a table of all the possible combinations of k and n, and which combinations are divisible by 3 and/or 5. All the remaining k values come from the four rows. Each of these rows has only one cell that is not divisible by 3 or 5, so all remaining primes must come from these four cells (The cells marked with j=). Note that for these four cells, the k values are all 2^j and n values are all 4-j.

[vjs]

I think the major point here is that eventually we will find a few of these very small k/n's that will be a product of two large primes. But the chances of them being close together???

It may be too soon to tell on some of these low-n... we will eliminate quite a few will trial factoring and the 991<n<50M sieve but what will be left???

I think it's starting to get to a point now where these small n are quite interesting.

[Mystwalker]

Thanks for that insight, Joe!

btw.:
I reached the 30 digit level of the last composite. No new factor...
If somebody else wants them, they are all free. I currently concentrate on 24737*2^991+1

[MikeH]

It's obvious from the stats pages that I've been doing some work in this area, but never got round to posting what. Here's my progress to date

Complete (P-1)
[Mon 21-Feb-2005 20:38:28]  P-1: Range      900-2000     ( 1100), 49, 1000000.0,   23 candidates in worktodo.ini
[Sun 06-Mar-2005 15:12:57]  P-1: Range     2000-5000     ( 3000), 49, 200000.0,   66 candidates in worktodo.ini
[Sun 06-Mar-2005 23:02:51]  P-1: Range     5000-8000     ( 3000), 49, 100000.0,   84 candidates in worktodo.ini
[Sun 06-Mar-2005 23:04:11]  P-1: Range     8000-11500    ( 3500), 49, 70000.0,   92 candidates in worktodo.ini
[Mon 21-Feb-2005 16:19:55]  P-1: Range    11500-12500    ( 1000), 49, 50000.0,   27 candidates in worktodo.ini
[Mon 21-Feb-2005 12:48:55]  P-1: Range    12500-13500    ( 1000), 49, 30000.0,   26 candidates in worktodo.ini
[Mon 21-Feb-2005 09:38:40]  P-1: Range    13500-14500    ( 1000), 49, 20000.0,   26 candidates in worktodo.ini
[Mon 21-Feb-2005 08:22:34]  P-1: Range    14500-15000    (  500), 49, 20000.0,   14 candidates in worktodo.ini
[Sat 19-Feb-2005 18:54:28]  P-1: Range    15000-20000    ( 5000), 49, 10000.0,  146 candidates in worktodo.ini
[Sat 19-Feb-2005 18:40:46]  P-1: Range    20000-25000    ( 5000), 49, 10000.0,  146 candidates in worktodo.ini
[Sun 20-Feb-2005 20:49:19]  P-1: Range    25000-25500    (  500), 49, 10000.0,   18 candidates in worktodo.ini
[Sun 20-Feb-2005 23:29:14]  P-1: Range    25500-27000    ( 1500), 49, 10000.0,   45 candidates in worktodo.ini
[Sun 20-Feb-2005 23:43:29]  P-1: Range    27000-27200    (  200), 49, 10000.0,    3 candidates in worktodo.ini
[Sun 20-Feb-2005 23:44:59]  P-1: Range    27200-27400    (  200), 49, 10000.0,    5 candidates in worktodo.ini
[Mon 21-Feb-2005 17:35:27]  P-1: Range    27400-40000    (12600), 49, 10000.0,  360 candidates in worktodo.ini
[Sun 27-Feb-2005 13:03:26]  P-1: Range    40000-41000    ( 1000), 49, 2000.0,   38 candidates in worktodo.ini
[Sun 27-Feb-2005 16:46:31]  P-1: Range    41000-45000    ( 4000), 49, 2000.0,  104 candidates in worktodo.ini
[Tue 01-Mar-2005 22:48:28]  P-1: Range    45000-50000    ( 5000), 49, 1000.0,  131 candidates in worktodo.ini
[Tue 01-Mar-2005 23:00:22]  P-1: Range    50000-60000    (10000), 49, 1000.0,  248 candidates in worktodo.ini
[Wed 02-Mar-2005 20:09:23]  P-1: Range    60000-70000    (10000), 49, 500.0,  307 candidates in worktodo.ini
[Wed 02-Mar-2005 23:31:35]  P-1: Range    70000-80000    (10000), 49, 500.0,  263 candidates in worktodo.ini
[Fri 04-Mar-2005 19:30:59]  P-1: Range    80000-90000    (10000), 49, 500.0,  293 candidates in worktodo.ini
[Sat 05-Mar-2005 13:02:15]  P-1: Range    90000-100000   (10000), 49, 500.0,  286 candidates in worktodo.ini

Complete (ECM)
[Sun 20-Mar-2005 21:08:45]  ECM: Range     2000-3000     ( 1000), 30,        18 candidates in worktodo.ini
[Sat 05-Mar-2005 16:29:27]  ECM: Range     3000-4000     ( 1000), 25,        22 candidates in worktodo.ini
[Sun 06-Mar-2005 23:17:50]  ECM: Range     4000-5000     ( 1000), 25,        29 candidates in worktodo.ini
[Wed 09-Mar-2005 22:53:46]  ECM: Range     5000-6000     ( 1000), 25,        23 candidates in worktodo.ini
[Thu 10-Mar-2005 20:30:51]  ECM: Range     6000-7000     ( 1000), 22,        31 candidates in worktodo.ini
[Fri 11-Mar-2005 15:08:36]  ECM: Range     7000-8000     ( 1000), 21,        24 candidates in worktodo.ini
[Sat 12-Mar-2005 00:17:05]  ECM: Range     8000-9000     ( 1000), 21,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 08:51:51]  ECM: Range     9000-10000    ( 1000), 20,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 14:11:21]  ECM: Range    10000-11000    ( 1000), 20,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 18:26:17]  ECM: Range    11000-14000    ( 3000), 20,        76 candidates in worktodo.ini
[Sun 13-Mar-2005 23:04:49]  ECM: Range    14000-18000    ( 4000), 20,       109 candidates in worktodo.ini
[Tue 15-Mar-2005 18:03:26]  ECM: Range    18000-20000    ( 2000), 20,        45 candidates in worktodo.ini
[Wed 16-Mar-2005 22:21:41]  ECM: Range    20000-25000    ( 5000), 20,       126 candidates in worktodo.ini

In progress (ECM)
[Mon 28-Mar-2005 12:20:04]  ECM: Range     3000-4000     ( 1000), 30,        15 candidates in worktodo.ini

So everything n<100K has been P-1ed to a 'value' of at least 500. Everything n<25K has been ECMed to at least 20 digits.

I'm currently ECMing 3K<n<4K to 30 digits. When that's done I'll probably extend the range beyond 25K before trying anything deeper on n>4K.

...and before anyone says it ....why?..... Well it's something different.

[vjs]

Great work Mike,

I've been trying to track your progress thus far through the user info, but it's tough to tell what one is doing.. until they have submitted factors of course.

Joe, will probably send you some more factors soon, p<25T, I basically found 21 factors less than 100k, 411 less than 20M. Not sure how many are unique or ones that you havn't found but they are all in my fact.txt so we will see.

Any chance of doing some 991<n<50M stats for us sievers? Should I send you what I'm doing for stats thus far?

[MikeH]

Very quick update. Two factors found in 3000-4000 range.

Complete (ECM)
[Sun 20-Mar-2005 21:08:45]  ECM: Range     2000-3000     ( 1000), 30,        18 candidates in worktodo.ini
[Mon 28-Mar-2005 12:20:04]  ECM: Range     3000-4000     ( 1000), 30,        15 candidates in worktodo.ini
[Sun 06-Mar-2005 23:17:50]  ECM: Range     4000-5000     ( 1000), 25,        29 candidates in worktodo.ini
[Wed 09-Mar-2005 22:53:46]  ECM: Range     5000-6000     ( 1000), 25,        23 candidates in worktodo.ini
[Thu 10-Mar-2005 20:30:51]  ECM: Range     6000-7000     ( 1000), 22,        31 candidates in worktodo.ini
[Fri 11-Mar-2005 15:08:36]  ECM: Range     7000-8000     ( 1000), 21,        24 candidates in worktodo.ini
[Sat 12-Mar-2005 00:17:05]  ECM: Range     8000-9000     ( 1000), 21,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 08:51:51]  ECM: Range     9000-10000    ( 1000), 20,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 14:11:21]  ECM: Range    10000-11000    ( 1000), 20,        22 candidates in worktodo.ini
[Sat 12-Mar-2005 18:26:17]  ECM: Range    11000-14000    ( 3000), 20,        76 candidates in worktodo.ini
[Sun 13-Mar-2005 23:04:49]  ECM: Range    14000-18000    ( 4000), 20,       109 candidates in worktodo.ini
[Tue 15-Mar-2005 18:03:26]  ECM: Range    18000-20000    ( 2000), 20,        45 candidates in worktodo.ini
[Wed 16-Mar-2005 22:21:41]  ECM: Range    20000-25000    ( 5000), 20,       126 candidates in worktodo.ini

In progress (ECM)
[Sat 02-Apr-2005 15:06:22]  ECM: Range     4000-5000     ( 1000), 30,        18 candidates in worktodo.ini
[Sat 02-Apr-2005 15:07:09]  ECM: Range    25000-30000    ( 5000), 20,       126 candidates in worktodo.ini

[Keroberts1]

what is currently being done with 24737*2^991+1 is anyone still trying to factor this? if so is there any way i can help?

[Mystwalker]

I'm currently finish the last few ECM curves for the 45 digit level.

You can see the progress here.

If you want, you can start the 50 digit effort. I will take a rest, though...

[Keroberts1]

what do i need ot help, just get me started and I'm on board.

[Mystwalker]

Depends on your personal ease/performance preferences.

The easy way:
Get Prime95/mprime v24.6 (24.11 currently contains a bug possibly affecting ECM).

You then have to do as described here (top posting should be enough).


The performance way:
Read the next ~20(?) postings.