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Old 2007-03-09, 18:09   #45
ET_'s Avatar
Aug 2002
Team Italia

2·29·83 Posts

Originally Posted by Kosmaj View Post
Congrats on a huge prime!!
Hey, Paul, congrtulations!

But now, the question: are we still in search of a million digits prime, or do we stop, due to lack of resources?

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Old 2007-03-09, 18:53   #46
NEBOJSA's Avatar
Sep 2005

7 Posts

Thats great news congratulation Paul
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Old 2007-03-10, 01:29   #47
paulunderwood's Avatar
Sep 2002
Database er0rr

367410 Posts

It has been re-verified at UTM. It's official.

As Jean suggested, we shall continue searching. We might get good luck, soon -- please keep on crunching.
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Old 2007-03-10, 06:55   #48
edorajh's Avatar
Oct 2003

7108 Posts

Congratulations!! Really nice prime!!
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Old 2007-03-10, 11:15   #49
davieddy's Avatar
Dec 2006

2·3·13·83 Posts

Excuse my ignorance, but how do you test for this prime?
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Old 2007-03-10, 11:42   #50
paulunderwood's Avatar
Sep 2002
Database er0rr

1110010110102 Posts

I am not quite sure about what you mean.

From the project's point of view we start with a list of candidates and eliminate them as quickly as possible, firstly by sieving the list and then, when sieving becomes slow, we move over to testing with LLR.

From a mathematical point of view, proving the number prime is done by using the Lucas-Lehmer-Riesel algorithm [1], underpinned by fast IBDWT multiplication [2] and an excellent implementation in code.

From your point of view, you can reserve a range to test here.

[1] Riesel, H., Lucasian Criteria for the Primality of N = h · 2n − 1, Math.
Comp. 23, 869–875 (1969)

[2] Percival, C., Rapid multiplication modulo the sum and difference of highly composite numbers, Math. Comp. 72, 387 - 395 (2003)

Last fiddled with by paulunderwood on 2007-03-11 at 12:55
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Old 2007-03-10, 15:28   #51
Mar 2004

418 Posts

Wow congratulations. Amazing find!
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Old 2007-03-10, 17:55   #52
em99010pepe's Avatar
Sep 2004

B0E16 Posts

Congratulations Paul!!!!

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Old 2007-03-12, 09:38   #53
Thomas11's Avatar
Feb 2003

22×32×53 Posts

Congratulations Paul!
That's a very nice prime!
You always find them when I'm off-line for a few days...

Good luck to all for our next (hopefully: million digits) prime!

Last fiddled with by Thomas11 on 2007-03-12 at 09:39
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Old 2008-04-16, 21:06   #54
paulunderwood's Avatar
Sep 2002
Database er0rr

2·11·167 Posts

I had word from John Blazek today that PrimeGrid found a 321 prime.

It was found as follows:

Username: Jiran
Account created: 20 Mar 2008 2:00:29 UTC
PC specs: Intel C2D @ 1.66 GHZ with 2 GB RAM running Linux.
Time: 55,753.70 seconds

WU sent: 22 Mar 2008 5:31:23 UTC
WU returned: 23 Mar 2008 7:57:28 UTC

Double Check
Username: Dave Pickles
Account created: 4 Apr 2007 5:15:56 UTC
PC specs: AMD Athlon XP 2500+ witn 512 MB RAM running Windows 2000
Time: 67,320.00 seconds

WU sent: 27 Mar 2008 13:25:21 UTC
WU returned: 2 Apr 2008 5:13:16 UTC

BTW, they both are Canadians!!! :)
It will be submitted to the top5000 primes soon for verification and logging.

It has 1,274,988 decimal digits and was where we expected it to occur

The prime is 3*2^4235414-1

Thanks to all involved with this find

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Old 2008-04-16, 21:50   #55
paulunderwood's Avatar
Sep 2002
Database er0rr

1110010110102 Posts

Here is the PrimePages entry. (It is being verified there at the moment.)
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