mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Lounge

Reply
 
Thread Tools
Old 2018-01-02, 07:36   #12
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

175528 Posts
Default

Quote:
Originally Posted by gophne View Post
Sagemath returns "123456791" as being a prime, and Prime95 is currently running on my machine with this number.
Quote:
Originally Posted by George M View Post
Ooohhhhhh...... you mean 2^1233333331 - 1 is composite..... ahhh k
Quote:
Originally Posted by gophne View Post
Running SAGEMATH code;

%time factor(1233333331)

returns that input as "prime"
Both 2^123456791-1 and 2^1233333331-1 have known factors. Thus, by rule 4, are not suitable guesses. For further inquires about the how, where, when, and why of this, please use a different thread. Also, why Prime95 is running on an exponent with a known factor, inquire in a different thread.

Both of your blind ignorance and insistence on being right is starting to feel like spam.
Uncwilly is offline   Reply With Quote
Old 2018-01-02, 08:27   #13
George M
 
Dec 2017

2×52 Posts
Default My Second Guess

982451707

If anyone is struggling to come up with a prime (for any reason) then you can head below:

http://www.primos.mat.br/2T_en.html

:)
George M is offline   Reply With Quote
Old 2018-01-02, 08:42   #14
GP2
 
GP2's Avatar
 
Sep 2003

50228 Posts
Default

Quote:
Originally Posted by gophne View Post
Sagemath returns "123456791" as being a prime, and Prime95 is currently running on my machine with this number.
Click here: 123456791, and then stop your machine.


Quote:
Originally Posted by ET_ View Post
The Mersenne you should test is 2^1233333331 - 1
The number 1,233,333,331 is indeed a prime number but 21,233,333,331−1 has a known factor, although you have to go to Mersenne.ca to see that, because such large numbers beyond 1 billion are beyond present capability for LL testing, and are not recorded by Primenet.

Last fiddled with by GP2 on 2018-01-02 at 08:45
GP2 is offline   Reply With Quote
Old 2018-01-02, 08:49   #15
George M
 
Dec 2017

2×52 Posts
Default

Quote:
Originally Posted by GP2 View Post
Click here: 123456791, and then stop your machine.




The number 1,233,333,331 is indeed a prime number but 21,233,333,331−1 has a known factor, although you have to go to Mersenne.ca to see that, because such large numbers beyond 1 billion are beyond present capability for LL testing, and are not recorded by Primenet.
I only chose that prime number because of all the 3’s in it haha
George M is offline   Reply With Quote
Old 2018-01-02, 08:53   #16
GP2
 
GP2's Avatar
 
Sep 2003

A1216 Posts
Default

Quote:
Originally Posted by George M View Post
982451707
First of all, 982,451,707 is a prime number, but 2982,451,707−1 has a factor, click here

Secondly, take a look at this list of known Mersenne primes, and consider how improbable it is that there would be a gap with no Mersenne primes from roughly 70+ million to nearly 1 billion.

Try a little harder to make reasonable guesses.
GP2 is offline   Reply With Quote
Old 2018-01-02, 08:55   #17
gophne
 
Feb 2017

101001012 Posts
Default

Quote:
Originally Posted by GP2 View Post
Click here: 123456791, and then stop your machine.




The number 1,233,333,331 is indeed a prime number but 21,233,333,331−1 has a known factor, although you have to go to Mersenne.ca to see that, because such large numbers beyond 1 billion are beyond present capability for LL testing, and are not recorded by Primenet.
Hi GP2

Thanks for the info/link.

I see what Uncwilly was saying now as well.

I will stop the current Prime95 process on my computer.

Regards

Last fiddled with by gophne on 2018-01-02 at 08:57
gophne is offline   Reply With Quote
Old 2018-01-02, 09:20   #18
George M
 
Dec 2017

2·52 Posts
Default Prime numbers not to pick

First of all, I will try and pick a number that is greater than a billion so they are reasonable (perhaps I should put my previous guesses in the PREDICT M50 thread). I will have my final guess at the end of this post.

Now, here are prime numbers p that should not be picked if

p \ \in \ [74243591, \ 74243681] or p \ \in \ [74294611, \ 74294861]

Also, after looking at the 46th and 47th mersenne prime and the gap between both exponents, I consider my previous guess reasonable, but it doesn’t mean anything if M_n is factored, my previous guess being equal to n.

So anyway, my final guess is.....
Hmmm....

1824261419

Last fiddled with by George M on 2018-01-02 at 09:29
George M is offline   Reply With Quote
Old 2018-01-02, 09:39   #19
ET_
Banned
 
ET_'s Avatar
 
"Luigi"
Aug 2002
Team Italia

72×97 Posts
Default

Quote:
Originally Posted by George M View Post
First of all, I will try and pick a number that is greater than a billion so they are reasonable (perhaps I should put my previous guesses in the PREDICT M50 thread). I will have my final guess at the end of this post.

Now, here are prime numbers p that should not be picked if

p \ \in \ [74243591, \ 74243681] or p \ \in \ [74294611, \ 74294861]

Also, after looking at the 46th and 47th mersenne prime and the gap between both exponents, I consider my previous guess reasonable, but it doesn’t mean anything if M_n is factored, my previous guess being equal to n.

So anyway, my final guess is.....
Hmmm....

1824261419
1824261419 has a factor

Last fiddled with by ET_ on 2018-01-02 at 09:40
ET_ is offline   Reply With Quote
Old 2018-01-02, 09:43   #20
George M
 
Dec 2017

2·52 Posts
Default

Quote:
Originally Posted by ET_ View Post
1824261419 has a factor
Man this is difficult...

Oh, and by the way, perhaps we should put a constraint on our guesses, such that our guesses should be less than 2^32 = 4294967296

………

It seems like 2^2252945257 - 1 may be prime. It has a probability of 63.7945% of being prime!! We also have another mersenne number with the exact probability: 2^2685457421 - 1. Funny that.

Last fiddled with by George M on 2018-01-02 at 10:06 Reason: Should be less than 2^32 because otherwise mersenne.ca can’t compute it
George M is offline   Reply With Quote
Old 2018-01-02, 09:46   #21
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(3,3^1118781+1)/3

902810 Posts
Default

Batalov is offline   Reply With Quote
Old 2018-01-02, 09:53   #22
George M
 
Dec 2017

2×52 Posts
Default

Quote:
Originally Posted by Batalov View Post
Who ever said otherwise? XD
George M is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stockfish game: "Move 9 poll", not "move 2^74,207,281-1 discussion" MooMoo2 Other Chess Games 1 2016-10-25 18:03
Stockfish game: "Move 8 poll", not "move 3.14159 discussion" MooMoo2 Other Chess Games 5 2016-10-22 01:55
Stockfish game: "Move 5 poll", not "move 0 discussion" MooMoo2 Other Chess Games 0 2016-10-05 15:50
Stockfish game: "Move 4 poll", not "move 100 discussion" MooMoo2 Other Chess Games 0 2016-09-28 19:51
Stockfish game: "Move 2 poll", not "move 2 discussion" MooMoo2 Other Chess Games 0 2016-09-19 19:56

All times are UTC. The time now is 21:32.

Tue Jun 2 21:32:06 UTC 2020 up 69 days, 19:05, 3 users, load averages: 2.15, 1.99, 2.03

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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.