-----Original Message-----
From: Nathan Russell <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
Date: 31 July 2001 19:51
Subject: Mersenne: M(2) - composite?!
>Hi all,
>
>I'm a bit puzzled. The other day, I donated blood and kept my mind
>busy by doing LL tests on a few exponents mentally. I kept getting
>the result that the LL test for M(2) ends up resulting in a repeating
>value of -1, and certainly cannot ever become zero. Am I missing
>something really obvious? I confirmed it on paper later to make sure
>I didn't make a mistake in the mental math.
>From <http://mersenne.org/math.htm> (brackets and exponentiation added for
the sake of clarity)
The Lucas-Lehmer primality test is remarkably simple. It states that 2**P-1
is prime if and only if S(p-2) is zero in this sequence: S(0) = 4, S(N) =
S(N-1)**2 - 2 mod 2**P-1.
If P=2 then S(P-2) is S(0) is 4 which is clearly not 0. It's not even 0 mod
3
However <http://www.utm.edu/research/primes/mersenne.shtml#test> does state
the P must be odd. So I guess the mersenne.org page is wrong.
>Nathan
Daran
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