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

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 slightly

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

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 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

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 usual

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 allows us to