From: mpd@netcom.com (Mike Duvos)
Date: Mon, 11 Apr 94 19:01:49 PDT
To: Cypherpunks@toad.com
Subject: Re: Classic Math gone wrong...Re: (n!+1)^(1/2)
In-Reply-To: <Pine.3.87.9404111838.A11608-0100000@crl.crl.com>
Message-ID: <199404120202.TAA06360@mail.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


> On Mon, 11 Apr 1994, Peter Wayner wrote:
 
> > Is there a largest prime number? 
> > If there is then collect all primes, p1...pn and multiply them
> > together p=p1*p2*...*pn. p+1 is not divisible by p1...pn. Therefore
> > p+1 is a prime. Therefore there is no largest prime number. 
 
> That's cool, why doesn't anyone use this to generate large prime numbers?
> I can see great potential for this one.  
>  Awaiting scorching flames,
>  Jeremy

The product of a bunch of primes plus one is not necessarily prime.  It
just contains a prime factor not in the primes multiplied together.  When
looking for a large prime number in some range of integers, it is
computationally more efficient to simply strobe upwards from some starting
point testing for primality than it is to try to generate the prime
directly using a mathematical formula. 

-- 
     Mike Duvos         $    PGP 2.3a Public Key available    $
     mpd@netcom.com     $    via Finger.                      $