The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Inactive » math-history-list

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: 1 as a prime number
Replies: 11   Last Post: Dec 9, 1997 11:13 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
John Conway

Posts: 2,238
Registered: 12/3/04
Re: 1 as a prime number
Posted: Dec 8, 1997 4:00 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On Mon, 8 Dec 1997, mark snyder wrote:

> At 9:58 PM -0200 12/7/97, Julio Gonzalez Cabillon wrote:
> >At 07:47 PM 05/12/1997 GMT, Mark Snyder wrote:
> >>I have heard that until about 1800, 1 was considered to be a prime number.
> >>Is this correct?

> >
> >Not quite! JGC

> So what *is* correct?
> mark snyder

I answered this at some length a few days ago. The tradition
before this century (dating back to Euclid's Elements) was indeed
to count 1 as a prime, and even Lehmer's 1914 list of prime numbers to
10 million does so. But the many inconveniences it causes have
led people this century to put it into a new category, and call
it a "unit" rather than a prime.

John Conway

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.