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Old 2017-04-23, 19:51   #1
Vicodin
 
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"Anastasia"
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Question Testing my numbers

Hello everybody!

I'm new in GIMPS. I want to know if I can test prime numbers in this program?
I know some prime numbers like 2^p, where p is about several hundred billion.
So testing 2^p - 1 is my dream :3 Hope my numbers are prime... :)
Can I do it?

Best regards,
Anastasia
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Old 2017-04-23, 20:56   #2
VictordeHolland
 
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Welcome to the mersenneforum!

There are multiple programs available to test primality of candidate numbers. For Mersenne numbers (2^P -1, with P prime) Prime95 is the easiest to start with.
You can download it from:
https://www.mersenne.org/download/
You can join GIMPS if you like, a coordinated effort for finding new Mersenne primes.

Testing a Mersenne candidate for primality, a so called Lucas-Lehmer test (usually shorted to LL-test) takes a couple of days on the fastest computers, to several weeks (or even months) on older models. Testing candidates with more than 100million digits takes years on a desktop computer and is not recommended if you just started. Testing billion digit numbers is not feasible with the current hardware.
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Old 2017-04-23, 21:32   #3
kladner
 
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Welcome, and Happy Number Crunching!
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Old 2017-04-23, 21:41   #4
ATH
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Quote:
Originally Posted by Vicodin View Post
Hello everybody!

I'm new in GIMPS. I want to know if I can test prime numbers in this program?
I know some prime numbers like 2^p, where p is about several hundred billion.
So testing 2^p - 1 is my dream :3 Hope my numbers are prime... :)
Can I do it?

Best regards,
Anastasia
Unfortunately there is no program that can run a primality test on 2p-1 for p>100,000,000,000 (100 billion).

The limit for Prime95 is around 595 million, and one such test will take 6+ months even on the fastest computers, and years on "normal" computers. Mlucas might be able to go a little higher, but no where near 100 billion.

You can trial factor your number and hope to find a factor (but that will kill your dreams about the number being prime). In the "Operation Billion Digits" forum there are software like Mfactor and factor5, and I believe those can trialfactor in those ranges.

Last fiddled with by ATH on 2017-04-24 at 03:14
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Old 2017-04-24, 01:13   #5
Uncwilly
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If you are thinking of testing 2(2^127-1)-1, there is no way to test it for many, many years to come.
http://mersennewiki.org/index.php/M12
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Old 2017-04-24, 01:23   #6
Prime95
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Quote:
Originally Posted by Uncwilly View Post
If you are thinking of testing 2(2^127-1)-1, there is no way to test it for many, many years to come.
http://mersennewiki.org/index.php/M12
That page needs updating. I thing it has been trial factored to 2^185 or so by mmff.
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Old 2017-04-24, 01:36   #7
a1call
 
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Quote:
Originally Posted by Uncwilly View Post
If you are thinking of testing 2(2^127-1)-1, there is no way to test it for many, many years to come.
http://mersennewiki.org/index.php/M12

Quote:
Now it can be done on a "smart phone" in under one second.
Is that a reference to a actual app or just a computing power statement?
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Old 2017-04-24, 01:39   #8
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Quote:
Originally Posted by Prime95 View Post
That page needs updating. I thing it has been trial factored to 2^185 or so by mmff.
think *. Also, noting that 2^1-1 is not 2, and that 2 is not a mersenne prime, and that 2^2-1 is not 7 might help.

Last fiddled with by science_man_88 on 2017-04-24 at 01:39
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Old 2017-04-24, 01:44   #9
a1call
 
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Quote:
Originally Posted by science_man_88 View Post
think *. Also, noting that 2^1-1 is not 2, and that 2 is not a mersenne prime, and that 2^2-1 is not 7 might help.
Well we know who to blame:

http://mersennewiki.org/index.php?ti...action=history

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Old 2017-04-24, 01:57   #10
a1call
 
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A search brought Nap 1 as an iphone app with arbitrary precision up to 40k and it is free.
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Old 2017-04-24, 02:02   #11
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110000T is reported as the upper k in the last posting the the operazione doppi mersenne results thread for it that I found.
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