mersenneforum.org  

Go Back   mersenneforum.org > Search Forums

Showing results 1 to 25 of 418
Search took 0.06 seconds.
Search: Posts Made By: bur
Forum: Miscellaneous Math 2021-11-27, 07:53
Replies: 7
Views: 494
Posted By bur
Interesting idea, I tried to find an example for...

Interesting idea, I tried to find an example for d_s > 6 but there were none up to d_s = 102. I only tested the smallest possible C with that d_s.

I did the search manually though as I was too...
Forum: Homework Help 2021-11-26, 14:32
Replies: 23
Views: 3,979
Posted By bur
And another one: Show that {p-1\choose...

And another one:

Show that {p-1\choose k}\equiv -1^k \pmod p

It probably shouldn't use Wilson's theorem since that only comes in the next section in the book.

I tried to write it as a...
Forum: And now for something completely different 2021-11-26, 06:57
Replies: 71
Views: 8,515
Posted By bur
To be honest, I also don't get it. The search...

To be honest, I also don't get it. The search limit is 10,800,000 but some numbers in the 6-8M range have not been checked yet (or at least it's not documented).
Forum: Proth Prime Search 2021-11-22, 16:32
Replies: 21
Views: 6,986
Posted By bur
Once again, a status update with no new prime: ...

Once again, a status update with no new prime:

Sieving
All n < 10,000,000 have been sieved to 800e12.
Last reported time per factor: approx. 12,000 s

76,167 candidates (1.6%) are left in the...
Forum: Homework Help 2021-11-21, 05:54
Replies: 23
Views: 3,979
Posted By bur
I know, I wrote just that... ;) I didn't...

I know, I wrote just that... ;)


I didn't think of that. But in that case it still only works for powers of 2 as factors.


Thanks, this is the answer to my question, but seeing it, I think...
Forum: Homework Help 2021-11-20, 08:26
Replies: 23
Views: 3,979
Posted By bur
Another problem came up. The exercises deal with...

Another problem came up. The exercises deal with showing that a^x is congruent to 1 (or a) mod c, where c is a composite number:

a^21 == a (mod 15) for all a

This is not a problem yet, but what...
Forum: Data 2021-11-17, 19:00
Replies: 79
Views: 8,871
Posted By bur
Old thread, but at least somewhat connected to my...

Old thread, but at least somewhat connected to my question:

I just got assigned a C-PRP on a number below the wavefront and saw the factor in question should have been found by P-1 20 years ago....
Forum: And now for something completely different 2021-11-17, 11:28
Replies: 71
Views: 8,515
Posted By bur
When looking at the stats...

When looking at the stats (https://www.kurtbeschorner.de/#rprimes) I noticed that the ranges 6M-7M and 7M-8M are not yet 100% completed but have a few exponents with status "unknown". Is there a...
Forum: Data 2021-11-12, 16:39
Replies: 119
Views: 10,183
Posted By bur
Ok, thanks. And one more question, this time...

Ok, thanks.

And one more question, this time hopefully a genuine problem: the script chose various P-1 jobs with B1 smaller than the actual work done. For example M52757...
Forum: Data 2021-11-11, 11:48
Replies: 119
Views: 10,183
Posted By bur
Some more testing revealed that indeed the size...

Some more testing revealed that indeed the size of the exponent determines whether or not the worker will run multithreaded. Is that a bug?
Forum: Data 2021-11-11, 08:38
Replies: 119
Views: 10,183
Posted By bur
I have a problem with multithreading. Initially I...

I have a problem with multithreading. Initially I was running P+1 with 2 workers on exponents in the 10^6 range and each worker ran 5 threads, fully utilizing the 10-core CPU. Then I added some 50000...
Forum: Data 2021-11-08, 21:33
Replies: 119
Views: 10,183
Posted By bur
Finally figured it out, I had to update to 30.6...

Finally figured it out, I had to update to 30.6 ...



I tried using the script to get P+1 to run, but I only get "illegal line in worktodo.txt" for each line. Doesn't matter whether I put them...
Forum: Software 2021-11-06, 06:36
Replies: 304
Views: 67,978
Posted By bur
That means it's 5% slower but allows for p up to...

That means it's 5% slower but allows for p up to 2^64? So if I don't need such large p, I'd better use the older version? Or is it only slower if you actually use p > 2^52?
Forum: Math 2021-11-01, 19:28
Replies: 10
Views: 2,239
Posted By bur
I know this thread is old, but I couldn't find...

I know this thread is old, but I couldn't find any other explanation more detailed than

A 41 digits for M14731 (https://www.mersenne.org/report_exponent/?exp_lo=14731&full=1) was found via ECM...
Forum: Software 2021-10-30, 06:11
Replies: 1
Views: 97
Posted By bur
pfgw factorial testing too slow?

I had done some factorial prime testing with PRPnet (http://prpnet.primegrid.com:12002/server_stats.html) with i5 and i3 CPUs before and a test took about 25-30 hours.

Now recently I began testing...
Forum: Riesel Prime Search 2021-10-25, 17:34
Replies: 290
Views: 51,516
Posted By bur
Thanks for moving the post. Who knows, it's not...

Thanks for moving the post.
Who knows, it's not like where GIMPS is currently at where 20M+ consecutive candidates are composite - at least I don't think so.



I always forget the estimate for...
Forum: Lone Mersenne Hunters 2021-10-24, 11:56
Replies: 1,985
Views: 270,874
Posted By bur
Nothing spectacular, but the first P-1 tests I...

Nothing spectacular, but the first P-1 tests I did in a while and the first to finish stage 1 returned:

[Worker #3 Oct 24 07:53] P-1 found a factor in stage #1, B1=779000.
[Worker #3 Oct 24...
Forum: Riesel Prime Search 2021-10-22, 17:44
Replies: 290
Views: 51,516
Posted By bur
New Primorial Prime found

Recently a new -1 type primorial prime was found at PRPNet.

3267113# - 1 (https://primes.utm.edu/primes/page.php?id=132758)

It has 1418398 digits, making it the largest known one. The last -1...
Forum: CADO-NFS 2021-10-22, 17:17
Replies: 72
Views: 14,156
Posted By bur
I finished the uniques ratio for a large set of...

I finished the uniques ratio for a large set of different q-min/q-max settings. The data is attached as an xslx file, zipped since for some reason the forum software didn't like the file....
Forum: Factoring 2021-10-18, 16:17
Replies: 60
Views: 4,950
Posted By bur
Once again the factoring times increased...

Once again the factoring times increased significantly. I'm at 1281979*2^632+1 and the 179 digits co-factor took nearly 24 hours. I used the optimized c140 params as basis with slightl adjustment as...
Forum: Proth Prime Search 2021-10-11, 07:14
Replies: 6
Views: 996
Posted By bur
Interesting, I didn't know about Pierpont primes....

Interesting, I didn't know about Pierpont primes. Did you check for ((x)G))F divisibility? The chances are slim, but you never know...
Forum: Msieve 2021-10-08, 15:46
Replies: 185
Views: 53,750
Posted By bur
This c163 poly is close to the record-holder with...

This c163 poly is close to the record-holder with cownoise score of 1.081e-12 vs. 1.096e-12. Maybe it can be spun towards a new record? I tried EdH's spin script but it changed nothing.


n:...
Forum: CADO-NFS 2021-10-07, 16:52
Replies: 72
Views: 14,156
Posted By bur
Total - Uniques - Duplicates - Ratio 10-100M...

Total - Uniques - Duplicates - Ratio

10-100M
214,512,998 - 153,030,781 - 61,482,217 - 71,34%

11-105M
219,448,738 - 158,516,513 - 60,932,225 - 72,23%

12-110M
224,369,197 - 163,859,554 -...
Forum: Aliquot Sequences 2021-10-06, 06:26
Replies: 136
Views: 46,462
Posted By bur
I think it would be a very interesting number...

I think it would be a very interesting number since 276 is both the smallest open-ended aliquot-sequence which also makes it part of the Lehmer 5. But since I don't have any means to sieve this it...
Forum: Aliquot Sequences 2021-10-02, 16:42
Replies: 3,147
Views: 262,683
Posted By bur
Nice, let's hope the 7 will vanish....

Nice, let's hope the 7 will vanish....
Showing results 1 to 25 of 418

 
All times are UTC. The time now is 00:19.


Tue Nov 30 00:19:18 UTC 2021 up 129 days, 18:48, 0 users, load averages: 0.97, 1.31, 1.26

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.