20201009, 12:46  #463  
"James Heinrich"
May 2004
exNorthern Ontario
C82_{16} Posts 
Quote:


20201010, 13:14  #464 
Jul 2018
Martin, Slovakia
415_{8} Posts 
Poor P1 tool not working properly, I think
I have tried to use the tool with these search parameters:
4,000,000  4,999,999; Probability 0  10 %; Order by probability It returns an empty table, but it shouldn't. M4087873 is listed with 2.799 % probability, meaning it should appear in the table. If I understand the working of the tool correctly, it should return lots of exponents. If I don't, please correct me. 
20201010, 16:18  #465 
"James Heinrich"
May 2004
exNorthern Ontario
2·1,601 Posts 
Thanks, there was a bug that prevented some exponents from appearing when they should.

20201010, 17:29  #466 
Aug 2020
113 Posts 
There might also be a bug with LL status. If you search with parameters 4e75e7, 0%10%, 1 test, more than 500 results will show up, however all exponents under 5e7 are already doublechecked.
Last fiddled with by Ensigm on 20201010 at 17:31 
20201010, 18:47  #467 
"James Heinrich"
May 2004
exNorthern Ontario
3202_{10} Posts 

20201014, 15:41  #468 
Jul 2003
wear a mask
2·743 Posts 
I broke the calculator again...
Please see the screen shot: almost every
Before anyone asks, I was considering the estimate of successful trial factoring (1/bitlevel) vs. the anecdotal estimate (1/100). If someone were to do tiny amounts of P1, only reporting the factors found, could that be enough to reduce the odds of successful trialfactoring to the supposedly observed result? Last fiddled with by masser on 20201014 at 15:43 
20201014, 16:27  #469  
"James Heinrich"
May 2004
exNorthern Ontario
6202_{8} Posts 
Quote:
The calculation iterates through many combinations of bounds, at each step aiming to get a bit closer at the next iteration. This works well when the process starts reasonably near the optimal bounds, it (as you can see) works very poorly (in the current implementation) when you start with bounds for ~5% and try to aim for 0.33%. I'll have to play with it and see what I can figure out. Thanks for reporting. 

20201014, 18:24  #470  
Aug 2020
113 Posts 
Quote:
A tiny P1 of (B1, B2)=(9500, 143000) has a 0.33% prior possibility of finding a factor of 105000001 that is larger than 2^{76} , according to the same tool you were using. However, to reduce the trial factoring success rate of the next bit level by 0.33% (or 0.3%), you need a P1 run that has a prior probability of 0.33% (or 0.3%) to find a factor from 2^{76} to 2^{77}. A P1 run of (B1, B2)=(450368, 11259212) has a 3.22%2.91%=0.31% probability of finding a factor in that bit range. It costs 6 GHzdays, which is quite close to a "normal" P1, not a "tiny" one. Conclusion: Based on calculations provided by mersenne.ca P1 probability tool, unreported tiny P1 runs may play a factor (no pun intended) in the phenomenon of observed TF success rate being short of prediction, but they are very unlikely to be the main reason. Last fiddled with by Ensigm on 20201014 at 18:35 

20201015, 18:55  #471 
Nov 2014
2·7 Posts 
PRP for exponent not shown
M20825573 does not show my (unnecessary) PRP run, which I reported a few days ago. There seems to be a bug. Please compare the output of mersenne.ca with mersenne.org.

20201015, 19:30  #472  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2^{3}·3·373 Posts 
Quote:


20201015, 20:26  #473 
Nov 2014
2×7 Posts 
Yes, but it doesn't show up on the top right in "Latest Primenet details". It isn't important, but to me it looks like a bug. And I assume there are not many numbers which have both LL/DC and PRP, so it could be an interesting edge case.

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Small inconsistencies between mersenne.org and mersenne.ca factor databases  GP2  mersenne.ca  44  20160619 19:29 
mersenne.ca (ex mersennearies.sili.net)  LaurV  mersenne.ca  8  20131125 21:01 
GaussianMersenne & EisensteinMersenne primes  siegert81  Math  2  20110919 17:36 
Mersenne Wiki: Improving the mersenne primes web site by FOSS methods  optim  PrimeNet  13  20040709 13:51 