Topic: 2(43,112,609-1)

[toasty0]

UCLA discovers gigantic prime number
13-million digit finding makes mathematicians eligible for $100,000 prize
The Associated Press
updated 10:22 a.m. PT, Sat., Sept. 27, 2008
LOS ANGELES - Mathematicians at UCLA have discovered a 13-million-digit prime number, a long-sought milestone that makes them eligible for a $100,000 prize.

The group found the 46th known Mersenne prime last month on a network of 75 computers running Windows XP. The number was verified by a different computer system running a different algorithm.

"We're delighted," said UCLA's Edson Smith, the leader of the effort. "Now we're looking for the next one, despite the odds."

It's the eighth Mersenne prime discovered at UCLA.

Primes are numbers like three, seven and 11 that are divisible by only two whole positive numbers: themselves and one.

Mersenne primes — named for their discoverer, 17th-century French mathematician Marin Mersenne — are expressed as 2P-1, or two to the power of "P" minus one. P is itself a prime number. For the new prime, P is 43,112,609.

Thousands of people around the world have been participating in the Great Internet Mersenne Prime Search, or GIMPS, a cooperative system in which underused computing power is harnessed to perform the calculations needed to find and verify Mersenne primes.


The $100,000 prize is being offered by the Electronic Frontier Foundation for finding the first Mersenne prime with more than 10 million digits. The foundation supports individual rights on the Internet and set up the prime number prize to promote cooperative computing using the Web.

Large prime numbers serve as the foundation for the cryptological techniques used to keep online transactions and coded communications secure — although the current generation of crypto codes doesn't require numbers quite as big as the one discovered by UCLA.

The Electronic Frontier Foundation's prize could be awarded to the researchers when the new prime is published, probably next year.

This report was supplemented by msnbc.com.


© 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
URL: http://www.msnbc.msn.com/id/26914730/

[Czar Mohab]

So, without going beyond what the article here reads, we have a 13 million didgit number, for simplicity's sake we'll call X, derived from the equation :

2^P-1 = X

Where P is a prime number and
P=43,112,609

So, if X is also a prime number, can I have my $100,000 for writing:

2^X-1 = Y

Where Y is, well, a really big number that is also prime.

Or do I actually have to crank out 2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2.... until I get to first X (since, well, the WINXP compy I'm at now doesn't handle such big numbers) and then finally Y? If I do it all by hand (pen and paper) can I have $1M? Or more?

More importantly, when we send out our next space probe that broadcasts our knowledge of prime numbers, will this new one be included, perhaps allowing the aliens that have deemed us unworthy to finally say, "We can make contact now, they've found a new one!" or will it be excluded as to fraggin' long?

Czar "I wonder what it looks like in binary," Mohab who adds that Microshaft's calculator said, "Nope. Not gunna do that," when I tried.

[FCM_SFHQ_XC]

Probably would be easier to write a mathematical java program to work out that math

[toasty0]

Probably would be easier to write a mathematical java program to work out that math

Why java and not C++ which is closer to the metal and will compile faster.

[FCM_SFHQ_XC]

Well either java or C++, I just happen to mention java since the last program I wrote this week was in java so java was closer to the top of my head I guess.. either though will do.

[toasty0]

Well either java or C++, I just happen to mention java since the last program I wrote this week was in java so java was closer to the top of my head I guess.. either though will do.

Wanna really show your programming chops I suggest coding in Assembler. 

[FCM_SFHQ_XC]

Well either java or C++, I just happen to mention java since the last program I wrote this week was in java so java was closer to the top of my head I guess.. either though will do.

Wanna really show your programming chops I suggest coding in Assembler.

meh..never really have had the time to fully study the assembler syntax. One of my future-programming-languages-to-learn goals though if I ever get the time down the road.

[toasty0]

This is a solution from a job interview question asking the applicant to find primes.

public static bool IsPrime(int number)
{
    // Throw out impossibles
    if (number < 2)
    {
        return false;
    }

    // Don't need to test above the square root of a number
    for (int i = 2; i < (number); i++)
    {
        // If remainder is 0, number is not prime
        if (number % i == 0)
        {
            // return false
            return false;
        }
    }

    // If all conditions are met, return true
    return true;
}

[Dracho]

Real men write Cobol and carry big iron.

[FCM_SFHQ_XC]

indeed? art thou sure?