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- Newsgroups: sci.math
- Path: sparky!uunet!wri!news
- From: roach@bikini.wri.com (Kelly Roach)
- Subject: Re: u(v^n)w prime puzzle
- Message-ID: <1992Aug19.153755.14825@wri.com>
- Sender: news@wri.com
- Nntp-Posting-Host: bikini.wri.com
- Organization: Wolfram Research, Inc.
- References: <l93702INNaq9@aludra.usc.edu>
- Date: Wed, 19 Aug 1992 15:37:55 GMT
- Lines: 38
-
- In article <l93702INNaq9@aludra.usc.edu> rmurphy@aludra.usc.edu (Bob
- Murphy) writes:
- > If there were such values of u, v, and w, then one could construct
- > arbitrarily large prime numbers. Since I have often heard
- > reference to "the largest known prime number", I would guess that
- > there are no such values. Now if only I had a proof.
-
-
- Not quite. The largest known prime number is 2^756839-1.
- But emphasize the word "known" here. In 1985, 2^216091-1 was
- the largest known prime number. It takes a few years to
- break each new "largest known prime number" record.
- There ARE infinitely many prime numbers and they do
- get arbitrarily large. A classic proof, due to Euclid is to
- take
-
- P = p1*p2*p3*...*pN+1
-
- where p1,p2,p3,...,pN are the primes you already know.
- The number P is not divisible by any of p1,p2,p3,...,pN.
- All the primes dividing P are new primes. Example:
- Suppose you know that 2,3,5,7,11,13 are prime. Then
-
- P = 2*3*5*7*11*13+1 = 30031 = 59 * 509
-
- gets you two new prime numbers 59 and 509. The process
- can be repeated ad infinitum.
-
-
- > So far I have only been able to show that if a solution exists
- > then v must be a multiple of 3.
-
-
- This is a good observation.
-
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-