[HM] Mathematics from the Birth of Numbers

Samuel S. Kutler (s-kutler@sjca.edu)
Fri, 5 Feb 1999 21:35:22 -0500 (EST)

Friends:

I was in the Naval Academy Library in Annapolis this week, and I read a
review of

Mathematics from the Birth of Numbers

by Jan Gullberg (1997). The review praised the book highly, and I found it
in that library, and I have the 1000 page book at home now. No doubt it
deserves a lot of praise. In leafing through it, however, I found on page
82 in the section on perfect numbers the following historical error:

Euclid & Nicomachus of Geresa suggested, and Euler proved in 1750 that if

M = 2^p - 1 is a Mersenne prime, then

N = M[2^(p-1)]

is a perfect number.

A. Nicomachus doesn't prove anything.

B. Euclid proved, rather than suggested, the theorem as his last propositon
in his number books (Book 9).

[Euclid would write 2^5 - 1: 1 + 2 + 4 + 8 + 16.]

C. Euler proved that every even perfect number is obtained by Euclid's method.

I hope that I typed those formulas correctly.

Best wishes from Annapolis,

Sam Kutler