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2020-10-02, 04:02   #1684
LaurV
Romulan Interpreter

Jun 2011
Thailand

22×7×11×29 Posts

Quote:
 Originally Posted by James Heinrich Unfortuantely (sic!) that's not at all uncommon, due in no small part to a buggy P-1 implementation in early versions of Prime95.
Scrolling (page changing) there doesn't work. Also: many old/small stuff was not found by P-1 because it was already found by TF to low limits (in spite of the fact that the middle of the table is not visible, the beginning and the end is, because the sorting by size/whatever, works well).

Last fiddled with by LaurV on 2020-10-02 at 04:02

2020-10-02, 10:30   #1685
James Heinrich

"James Heinrich"
May 2004
ex-Northern Ontario

C7316 Posts

Quote:
 Originally Posted by LaurV Scrolling (page changing) there doesn't work.
Thanks, fixed now.
Quote:
 Originally Posted by LaurV Also: many old/small stuff was not found by P-1 because it was already found by TF to low limits
No, this report only includes exponents where a NF-PM1 result was reported and then a factor was found to be in the range that the previous P-1 should have found but didn't.
For an example: M19,998,217 has a NF-PM1 reported on 2003-10-08, LL completed 2003-11-08, DC-LL completed 2007-12-03 (both a waste of time) and then 10 years after the failed P-1 a factor was found by TF on 2013-08-14.
When I generate data for this report I explicitly look for factors found after the P-1 was done.

2020-10-02, 11:29   #1686
Ensigm

Aug 2020

3·5·7 Posts

Quote:
 Originally Posted by James Heinrich data for this report I explicitly look for factors found after the P-1 was done.

Are you the maintainer of mersenne.ca? I think some exponents in the list are actually results of glitches in data conversion, such as 50077721. It might be better to exclude those cases where P-1 date is unknown.

i.e., if a P-1 date is unknown, we treat it as done after the factor discovery. If a factor discovery date is unknown, we treat it as discovered during or before the P-1 run.

Last fiddled with by Ensigm on 2020-10-02 at 11:35

2020-10-02, 18:26   #1687
James Heinrich

"James Heinrich"
May 2004
ex-Northern Ontario

61638 Posts

Quote:
 Originally Posted by Ensigm I think some exponents in the list are actually results of glitches in data conversion, such as 50077721
Thanks for highlighting a specific example. There was an illogic in part of my code that got the P-1 run and P-1 bounds disconnected. I have patched that and fixed it so it shouldn't happen any further. And that eliminates about 14k/16 exponents that were in the "missed by P-1" list.

 2020-10-05, 12:43 #1688 storm5510 Random Account     Aug 2009 U.S.A. 3×563 Posts From August 23rd. It may already be here somewhere. Anything shorter than 30 digits, I do not bother with... M100091029 has a 101.349-bit (31-digit) factor: 3228091182977790599237506837961 (P-1,B1=650000,B2=22000000)
 2020-10-05, 20:51 #1689 firejuggler     Apr 2010 Over the rainbow 1001101010112 Posts ryan did it again Code: Ryan Propper F-ECMFactor: 1270133764632902720778602923087552962031274925622407641153 / (ECM curve 1, B1=110000000, B2=900514153782, Sigma=11360005842630690070) as well as for 5231 and 5351 ( but slightly less impressive) Last fiddled with by firejuggler on 2020-10-05 at 20:53
 2020-10-07, 13:09 #1690 LaurV Romulan Interpreter     Jun 2011 Thailand 22×7×11×29 Posts As we were talking about ECM records, I was looking to see if my memory still serves me right about those 83 digits, and found that there are some misconcordances between this table and this table. We have all their lines, but sometimes with different names (usually, anonymous, when the right names should be provided, even if they are not members of gimps, that would be fair for the discoverers), while they do NOT have all our lines, probably some of our records were not reported to them (like Ryan's M2671 factor). Somebody may report our records to them, so they become part of the "all times/all kinds" record history (not me, the discoverer should do it, but if they are not interested, maybe James?).
 2020-10-07, 17:07 #1691 Jwb52z     Sep 2002 3×257 Posts P-1 found a factor in stage #2, B1=723000, B2=19528000. UID: Jwb52z/Clay, M100310531 has a factor: 54958127519802952206597652367 (P-1, B1=723000, B2=19528000), 95.472 bits.
 2020-10-10, 06:36 #1692 axn     Jun 2003 7×683 Posts Another big one. 42 digits, 138 bits Code: M3667249 has a factor: 343439538302947378252521531857403032501081 (P-1, B1=30000000, B2=600000000, E=12) Not my biggest, but still a top-40
2020-10-10, 11:44   #1693
James Heinrich

"James Heinrich"
May 2004
ex-Northern Ontario

1100011100112 Posts

Quote:
 Originally Posted by axn Another big one. 42 digits, 138 bits. Not my biggest, but still a top-40 M3667249 has a 137.979-bit (42-digit) factor: 343439538302947378252521531857403032501081 (P-1,B1=30000000,B2=600000000,E=12)
Wow, impressive, congrats!

2020-10-10, 15:58   #1694
storm5510
Random Account

Aug 2009
U.S.A.

110100110012 Posts

I was goofing with the GPU functions of GMP-ECM. The input cannot be larger than 2^1018. I was pulling test values out of the air when I came up with this:

Quote:
 Composite cofactor ((((2^943-1)/41884514890068404473)/21698431)/62209711)/164511353 has 241 digits
I am not sure how anyone would convert this to a single large number. Consider it a curiosity, amusement, or whatever.

Edit: I thought about Yafu, so I ran this:

Quote:
 yafu (2^^943-1)*41884514890068404473*21698431*62209711*164511353
And came up with this:

Quote:
 691547141158611815988660322245152254658444810391024156084685520265851892528698195573824658968142416474365688635818459535379264569959609451020315792308103892844793652170248778874582185260236045114390228299259879386132422860579103312328382466032643920718110437396847181215829653041151849017588990719779703721487849925242727519103

Last fiddled with by storm5510 on 2020-10-10 at 16:26

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