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From: budd@arizona.UUCP (tim budd)
Newsgroups: net.math
Subject: prime numbers (high school math)
Message-ID: <5587@arizona.UUCP>
Date: Fri, 21-Oct-83 18:50:39 EDT
Article-I.D.: arizona.5587
Posted: Fri Oct 21 18:50:39 1983
Date-Received: Sat, 22-Oct-83 16:33:39 EDT
Organization: CS Dept, U of Arizona, Tucson
Lines: 13

The recent comments on prime numbers recalls to mind a couple facts I
stumbled upon concerning prime numbers way back when I was in high school
(more years ago than I like to remember).  The first is truly trivial to
prove, although at the time I was impressed with myself for seeing it,
and is that prime numbers can all be expressed (along with a lot of non-
prime numbers) as 6n + or - 1.

The second "fact" is more difficult, however, and I have never seen a proof
of it (although I will admit I have never looked!).  That is that prime
numbers greater than 5 (again along with a lot of other numbers) can be
expressed as sqrt(1 + 24n).  Try it!  By the way, the sequence n which
when plugged into here results in prime numbers is itself interesting,
but has no more pattern to it than prime numbers themselves.