mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Blogorrhea > enzocreti

Reply
 
Thread Tools
Old 2018-12-05, 10:18   #1
enzocreti
 
Mar 2018

17·31 Posts
Default A yuge number

(2^7891456-1)*10^2375565+2^7891455-1


Is this number a probable prime or which is the smallest factor?
enzocreti is offline   Reply With Quote
Old 2018-12-05, 11:22   #2
axn
 
axn's Avatar
 
Jun 2003

113578 Posts
Default

Quote:
Originally Posted by enzocreti View Post
Is this number a probable prime
Almost certainly not.
Quote:
Originally Posted by enzocreti View Post
or which is the smallest factor?
Could be too big for us to find out.

Why don't you do a PRP test using PFGW and find out if it is (probable) prime or composite?
axn is offline   Reply With Quote
Old 2018-12-05, 13:23   #3
axn
 
axn's Avatar
 
Jun 2003

37·131 Posts
Default

No factors till 32*10^9. Quitting my attempt.
axn is offline   Reply With Quote
Old 2018-12-05, 13:36   #4
science_man_88
 
science_man_88's Avatar
 
"Forget I exist"
Jul 2009
Dumbassville

100000110000002 Posts
Default

Quote:
Originally Posted by enzocreti View Post
(2^7891456-1)*10^2375565+2^7891455-1


Is this number a probable prime or which is the smallest factor?
it won't have any factors in common with M3, M5,M11,M13, M283 , or M15413 to start. if it did then then the consecutive Mersenne numbers in question would have to share a factor. it also won't share factors with 2^15413+1 and a few other numbers. just using simple math.
science_man_88 is offline   Reply With Quote
Old 2018-12-06, 11:16   #5
enzocreti
 
Mar 2018

17·31 Posts
Default Program

Quote:
Originally Posted by axn View Post
No factors till 32*10^9. Quitting my attempt.
Can you tell me what program did you use?
enzocreti is offline   Reply With Quote
Old 2018-12-06, 13:29   #6
axn
 
axn's Avatar
 
Jun 2003

37×131 Posts
Default

Quote:
Originally Posted by enzocreti View Post
Can you tell me what program did you use?
A quick 2-line throwaway script written in PARI/GP
axn is offline   Reply With Quote
Old 2018-12-06, 13:59   #7
enzocreti
 
Mar 2018

17×31 Posts
Default code

Quote:
Originally Posted by axn View Post
A quick 2-line throwaway script written in PARI/GP

Can you give me the code?
enzocreti is offline   Reply With Quote
Old 2018-12-06, 14:42   #8
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

22·72·47 Posts
Default

Quote:
Originally Posted by enzocreti View Post
Can you give me the code?
Go write it for yourself. Prove to us that you are willing to do some actual work in proving your number schemes. We have been spoonfeeding your.

Last fiddled with by Uncwilly on 2018-12-06 at 14:43
Uncwilly is online now   Reply With Quote
Old 2018-12-06, 15:45   #9
axn
 
axn's Avatar
 
Jun 2003

113578 Posts
Default

Code:
mod_check(p)=my(r=Mod(2,p)^7891455); (r*2-1)*Mod(10,p)^2375565+r==1
forprime(p=2,,if(mod_check(p),print(p)))
Here you go...
axn is offline   Reply With Quote
Old 2018-12-06, 15:50   #10
enzocreti
 
Mar 2018

17×31 Posts
Default code

Quote:
Originally Posted by axn View Post
Code:
mod_check(p)=my(r=Mod(2,p)^7891455); (r*2-1)*Mod(10,p)^2375565+r==1
forprime(p=2,,if(mod_check(p),print(p)))
Here you go...

ok thanks
enzocreti is offline   Reply With Quote
Old 2018-12-06, 15:56   #11
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

24·3·193 Posts
Default

Why not use Sage for that, though?
Batalov is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Finding multiples of a real number that are close to a whole number mickfrancis Math 16 2017-03-01 07:17
Estimating the number of primes in a partially-factored number CRGreathouse Probability & Probabilistic Number Theory 15 2014-08-13 18:46
Number 59649589127497217 is a factor of Fermat number F7 literka Miscellaneous Math 73 2013-11-17 10:33
Number of distinct prime factors of a Double Mersenne number aketilander Operazione Doppi Mersennes 1 2012-11-09 21:16
Fermat number F6=18446744073709551617 is a composite number. Proof. literka Factoring 5 2012-01-30 12:28

All times are UTC. The time now is 06:52.

Tue Jan 26 06:52:26 UTC 2021 up 54 days, 3:03, 0 users, load averages: 3.07, 2.89, 2.79

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.