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 later" McCranie |
+--+



Unsubscribe  list info -- http://www.scruz.net/~luke/signup.htm



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 proved that they can't be square free.

From your analysis you can conclude that if Mn is *not* square-free,
then it must have an odd number of factors that are congruent to 3
(mod 4).

With M21, for example:

M21 = 2^21-1 = 7 * 7 * 127 * 337

Breaks down as:
7 * 7 = 49 == 1 (mod 4)
127 == 3 (mod 4)
337 == 1 (mod 4)

The previous conclusion can be generalized to simply:  All Mersenne
numbers greater than one must have an odd number of factors that are
congruent to 3 (mod 4).

-Don Leclair



Unsubscribe  list info -- http://www.scruz.net/~luke/signup.htm