Message boards : Problems and Help : how i can do my own primes?

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Message 126400 - Posted: 6 Feb 2019 | 21:33:29 UTC

Hi,I'm trying to find primes numbers of 383 * 2 ^ n +/- 1,
i don't know how to create a program to do it,
anyone can help me?

Crun-chi
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Message 126401 - Posted: 6 Feb 2019 | 21:39:15 UTC - in response to Message 126400.

First you need to create sieve file, so you eliminate as much as possible candidates who has factors.
What is left you need to process with LLR or Prime95 of PFGW programs, who can tell at the end is candidate prime or not.
You can get sieve file on minus side already done by Primegrid.
So you can start testing immediately. ( if it is not taken by someone else)
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271643232^131072+1 GENERALIZED FERMAT :)
93*10^1029523-1 REPDIGIT PRIME
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Message 126403 - Posted: 6 Feb 2019 | 22:19:44 UTC - in response to Message 126400.

Hi,I'm trying to find primes numbers of 383 * 2 ^ n +/- 1,
i don't know how to create a program to do it,
anyone can help me?

I would start by determining whether anyone else has already tested those numbers. You don't want to be testing numbers somebody has tested.

You also should determine whether people are currently testing the numbers you're thinking of. Not only is it rather impolite to do so if someone is actively testing the same numbers, but you're also going to duplicate work. There's (literally) an infinite amount of numbers out there to test. Why pick something that's already been tested or is being tested elsewhere?

You didn't mention what range of n you plan on testing, but 383*2^n+1 is part of PrimeGrid's PPS project, and I believe 383*2^n-1 is part of the Riesel Prime Search over at the Mersenne Forums.

Might I ask why you want to do this on your own? Knowing the "why" might enable people to give you better advice. For example, if your answer is "I'm looking for the fastest way to find a Top 5000 Prime", that information would be helpful because I could tell you that this is the wrong way to do that. But I need to know what your goal is to give you a good answer.
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Message 126421 - Posted: 7 Feb 2019 | 7:01:12 UTC - in response to Message 126403.

1º thanks for answer my question, and sorry for my english

2ºI'd like the first 100 n values for start,I'm doing this because my favourite number is 383,
that's only for fun.
I made the first 30 values
383*2^n+1 n=1-30, any primes except 28 that i don't know
383*2^n-1 n=1-30, values 2,8,12,16 and 30 i don't know

How i can search 383*2^n +/-1 in Primegrid for all people?

Michael Goetz
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Message 126427 - Posted: 7 Feb 2019 | 11:07:20 UTC - in response to Message 126421.

1º thanks for answer my question, and sorry for my english

2ºI'd like the first 100 n values for start,I'm doing this because my favourite number is 383,
that's only for fun.
I made the first 30 values
383*2^n+1 n=1-30, any primes except 28 that i don't know
383*2^n-1 n=1-30, values 2,8,12,16 and 30 i don't know

How i can search 383*2^n +/-1 in Primegrid for all people?

First of all, at PrimeGrid, you can't search for k=383 primes specifically. You can run our PPS-LLR project, which includes 383*2^n+1, but it's searching hundreds of k's, not just 383.

If you want to search 383 primes by yourself for small values of n, you can use just about anything as those can be checked very quickly. The LLR program, for example, can be used:

llr64 -d -q"383*2^30+1"

Note, however, that small numbers like this have all been checked many years ago.
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Message 126462 - Posted: 7 Feb 2019 | 17:10:35 UTC - in response to Message 126427.

If you have time,Can you do a step by step tutorial for 383*2^30+1 in LLR programm,
I was searching and I don't find any interesting information except this
[url]http://www.mersenneforum.org/attachment.php?attachmentid=797&d=1127311363
and isn't so good for me.[/url]

Michael Goetz
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Message 126465 - Posted: 7 Feb 2019 | 17:29:08 UTC - in response to Message 126462.

If you have time,Can you do a step by step tutorial for 383*2^30+1 in LLR programm,
I was searching and I don't find any interesting information except this
[url]http://www.mersenneforum.org/attachment.php?attachmentid=797&d=1127311363
and isn't so good for me.[/url]

Assuming you're running 64 bit Windows, download the latest "for MS Windows 64bit, CONSOLE APPLICATION". Currently that is this: http://jpenne.free.fr/llr3/cllr38lwin64.zip

Extract the file cllr64.exe from the zip file. From the directory to which you extracted the file, run this command:

cllr64 -d -q"383*2^30+1"

It should print out:

Error 2 while trying to create new process
APRCL primality test not available for 383*2^30+1
383*2^30+1 has a small factor : 3 !!

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Message 126467 - Posted: 7 Feb 2019 | 18:30:19 UTC - in response to Message 126465.

The CONSOLE APLICATION cllr381win64.zip can't work on my computer, also for 32 bits and olds versions.
But the MS Windows 64 bit, GUI it works only at LLR64,not at aprcl
what I can do?

Michael Goetz
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Message 126468 - Posted: 7 Feb 2019 | 18:34:33 UTC - in response to Message 126467.

The CONSOLE APLICATION cllr381win64.zip can't work on my computer, also for 32 bits and olds versions.
But the MS Windows 64 bit, GUI it works only at LLR64,not at aprcl
what I can do?

Did you extract cllr64.exe from the zip file?
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Message 126470 - Posted: 7 Feb 2019 | 18:58:39 UTC - in response to Message 126468.

yes, like 4 times and i got the sames results

Michael Goetz
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Message 126471 - Posted: 7 Feb 2019 | 19:24:17 UTC - in response to Message 126470.

yes, like 4 times and i got the sames results

Were you running it from a CMD window (also sometimes called a DOS window), or were you trying to run it directly from either the start box or a directory or file listing? It needs to be run from a CMD window. It's a command line program.

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Message 126477 - Posted: 7 Feb 2019 | 20:26:03 UTC - in response to Message 126471.

I was triying to run in the Desktop
With what command it be work in CMD?

Michael Goetz
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Message 126479 - Posted: 7 Feb 2019 | 20:35:13 UTC - in response to Message 126477.

I was triying to run in the Desktop
With what command it be work in CMD?

cmd will open a command window.

Within the command window, use the command I gave you.
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Message 126480 - Posted: 7 Feb 2019 | 20:43:13 UTC - in response to Message 126479.

I will try it in another laptop, crossing fingers

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Message 126484 - Posted: 7 Feb 2019 | 21:10:22 UTC

To get your feet wet, if you want to search for primes that won't be redoing anyone else's work, check out http://harvey563.tripod.com/ and specifically http://harvey563.tripod.com/GWlist.txt. You can search for Woodall primes of the form n*383^n-1. To do this you will need to learn how to sieve (using gcwsieve) and how to use llr. Fortunately you can do this with a lot of trial and error, but once you figure that out you will appreciate more how projects like this work.

Message boards : Problems and Help : how i can do my own primes?