Re: no square-free odd number can be perfect.
- --- In firstname.lastname@example.org,
Kermit Rose <kermit@...> wrote:
> we today can make an elementary and simple proof thatDescartes remarked on this in 1638. Moroever, he knew that
> no square-free odd number can be perfect
only one prime divisor may be raised to an odd power,
which follows from merely considering sigma(N) modulo 4.
gives a translation of part of his letter to Mersenne, which
I gave in French in an earlier posting.