20200704, 20:09  #771  
Just call me Henry
"David"
Sep 2007
Cambridge (GMT/BST)
1011010111010_{2} Posts 
Quote:


20200705, 02:13  #772 
Jun 2012
Boulder, CO
263 Posts 
In case anyone is interested, here's the full msieve log for 732541^471.

20200802, 20:05  #773 
Apr 2006
97 Posts 
The new list of roadblock composites is here
http://www.lirmm.fr/~ochem/opn/mwrb2100.txt and the old one is here http://www.lirmm.fr/~ochem/opn/old_mwrb2100.txt Most of the changes are due to the recent factorizations of sigma(3^660) and sigma(732541^46). Notably, the weight of sigma(6115909044841454629^16) drops from 79580833 to 67959517 and the weight of sigma(127^192) drops from 29196565 to 14190689. 
20200803, 16:05  #774 
Just call me Henry
"David"
Sep 2007
Cambridge (GMT/BST)
2·2,909 Posts 
Are the files available that contain all the factors used in the proof?
How do you check that all the composites hit have been trial factored to at least the assumed level given that pfn doesn't output a file containing the composites hit(I suppose you could extract them from the log)? Does it even matter if there are unfound small factors in nonroadblock composites apart from them causing gcd errors? 
20200809, 21:03  #775  
Apr 2006
97_{10} Posts 
My policy is to increase the lower bound by a factor 10^100 when the run takes less than one week.
A couple of years ago, it took 3 weeks to prove 10^2100. The goal of the run of july 2020 was to get the timing (it took 12 days) and to update the list of roadblocks. Some composites would have been needed in order to circumvent sigma(3^660) or sigma(732541^46) but are not needed elsewhere. They are not needed anymore and do not appear in the updated mwrb2100.txt Since the program was not aiming at a new lower bound, it was run with trial factoring up to 300 only, in order to catch the tiny factors that may cause the abundancy to exceed 2 (a higher trial limit or some ECM would slow things down). This produces a load of uninteresting factors. Trial factoring up to 10^10 is indeed required for roadblock composites. This is checked a posteriori. The list of useful factors has been updated: http://www.lirmm.fr/~ochem/opn/checkfacts.txt.gz Quote:
Most probably, the cofactor will be composite. In this case, a given factor \(P\) with \(d\) digits counts for \(d\) digits if \(P\) is in the unfactored part and counts for \(2d\) digits if \(P\) is in the factored part, because we can usually assume that \(P^2 \) divides the OPN. So finding \(P\) contributes only \(d\) digits to the 2100 digits, in only one or few branches of the proof tree. The composites worth considering are in mwrb2100.txt and t2100.txt 

20200810, 17:55  #776 
Dec 2017
111111_{2} Posts 
All of the remaining entries in the MWRB file have SNFS difficulty above 210.
That is about the upper limit of my resources and NFSNET has reserved the next one, so this is a good point to stop working on this file. 
20201022, 17:35  #777 
Sep 2008
Kansas
5^{2}·131 Posts 
Update on the OPN road blocks. The following are the number of composites remaining in the respective file along with the number queued for the grid.
Code:
File Entries Queued ==== ======= ====== t550 18 4 t600 137 6 t800 2475 10 I have a few numbers (mostly from t550 & t600) that are ready for SNFS but they will go to the larger sieve queues. I will wait for those queues to work through some of their numbers. 
20201023, 14:24  #778 
Oct 2007
Manchester, UK
10100111100_{2} Posts 
Can anyone refresh my memory about the amount of effort put into the MWRB numbers? When it gets put back up I thought I might have a go at running some ECM, but I wouldn't know what size factors to search for.

20201023, 16:47  #779  
Sep 2008
Kansas
5^{2}·131 Posts 
Quote:
I usually follow a couple dozen numbers at a time while I feed yoyo and NFS@Home. I don't touch any numbers beyond what NFS@Home can do on the 15e queue, say < SNFS280. 

20201026, 22:41  #780  
Jun 2012
Boulder, CO
407_{8} Posts 
Quote:
I've reported these to FactorDB; does Pascal's script/process periodically query the latest state from FactorDB? 

20201026, 23:47  #781  
Sep 2008
Kansas
5^{2}×131 Posts 
Quote:
https://www.mersenneforum.org/showpo...&postcount=464 

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