Re: Mersenne: Why can't we...

1999-07-09 Thread Brian J. Beesley
On 10 Jul 99, at 14:57, Peter Foster wrote: > When doing an LL test we are always calculating the > same series of numbers. The modulus is different, so > we can't use the result of one test to help with > another. I'm wondering why we don't do the following: > > Take 2 Mersenne numbers, m1 a

Re: Mersenne: Why can't we...

1999-07-09 Thread Lucas Wiman
> Take 2 Mersenne numbers, m1 and m2 (m1 < m2). > Do the usual LL series, but use as the modulus m1*m2. > At the appropriate step, check if the remainder is > divisible by m1. If so, then m1 is prime. > At the end, check if the remainder is divisible by > m2. If so, then m2 is prime. > This allow

Re: Mersenne: Why can't we...

1999-07-09 Thread Peter-Lawrence . Montgomery
Peter Foster asks: > When doing an LL test we are always calculating the > same series of numbers. The modulus is different, so > we can't use the result of one test to help with > another. I'm wondering why we don't do the following: > > Take 2 Mersenne numbers, m1 and m2 (m1 < m2). > Do the

Mersenne: Why can't we...

1999-07-09 Thread Peter Foster
When doing an LL test we are always calculating the same series of numbers. The modulus is different, so we can't use the result of one test to help with another. I'm wondering why we don't do the following: Take 2 Mersenne numbers, m1 and m2 (m1 < m2). Do the usual LL series, but use as the m

RE: Mersenne: Mersenne Numbers

1999-07-09 Thread Don Leclair - Toggle Software
Hello, > thus the numbers can never be the same above one > when the mersenne number mod 4 is always 3 and > the odd square mod 4 is always 1. Your analysis is correct but your conclusion is wrong. You've proved that all Mersenne numbers greater than 1 cannot be odd squares but you haven't pro

Mersenne Digest V1 #595

1999-07-09 Thread Mersenne Digest
Mersenne Digest Friday, July 9 1999 Volume 01 : Number 595 -- Date: Thu, 8 Jul 1999 00:52:45 -0400 (EDT) From: Lucas Wiman <[EMAIL PROTECTED]> Subject: Re: Mersenne: Repeating LL reminder > I know it's a

Re: Mersenne: Mersenne Numbers

1999-07-09 Thread Kris Garrett
--- Kris Garrett <[EMAIL PROTECTED]> wrote: > If it has not been proven that all mersenne numbers > greater than one is > prime free then here is a proof for you. > > 2^n-1 mod 4 = 3 while n > 1 because every 2^n while > n > 1 is divisible by 4 itself. > > On the other hand every odd square mo

Mersenne: Mersenne numbers

1999-07-09 Thread Will Edgington
Kris Garrett writes: Has it been proven that all mersenne numbers greater than one are square free? Depends on your definition of 'Mersenne numbers'. If you include composite exponents, M(6) = 2^6 - 1 = 63 = 3*3*7 is not square free. If you include only prime exponents, then you don't ne

Mersenne: Mersenne Numbers

1999-07-09 Thread Kris Garrett
If it has not been proven that all mersenne numbers greater than one is prime free then here is a proof for you. 2^n-1 mod 4 = 3 while n > 1 because every 2^n while n > 1 is divisible by 4 itself. On the other hand every odd square mod 4 is always 1 because: if the odd number mod 4 is 1 then: n

Re: Mersenne: Head's algorithm for multiplying mod n

1999-07-09 Thread Jud McCranie
At 06:51 PM 7/9/99 +0100, Brian J. Beesley wrote: >For reasonably small multi-precision numbers, Head's method is >actually very good, if you're working on a true RISC processor with >no integer multiply instruction. I started using Head's algorithm in 1981 on my Apple II. It was better than

Re: Mersenne: Mersenne numbers

1999-07-09 Thread Jud McCranie
At 10:16 AM 7/9/99 -0700, Kris Garrett wrote: >Has it been proven that all mersenne numbers greater than one are >square free? As far as I know, it has not been proven (and no repeated factors are known either). +--+ | Jud "program first and think late

Re: Mersenne: Head's algorithm for multiplying mod n

1999-07-09 Thread Brian J. Beesley
On 8 Jul 99, at 23:33, Lucas Wiman wrote: > >That is going to be a *lot* slower than FFT convolution, for numbers the size > >of the Mersenne numbers we're testing! FFT is O(n*log(n)) where n is the > >number of limbs in the numbers being multiplied. Head's method is O(n^2), > >with O being sli

Mersenne: Mersenne numbers

1999-07-09 Thread Kris Garrett
Has it been proven that all mersenne numbers greater than one are square free? _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com Unsubscribe & list in