Re: PrimeQ queries
- To: mathgroup at smc.vnet.net
- Subject: [mg24351] Re: [mg24213] PrimeQ queries
- From: "Greg Keogh" <greg at mira.net>
- Date: Sun, 9 Jul 2000 04:52:55 -0400 (EDT)
- References: <8jrcsg$e14@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Harvery,
> The two examples you give of numbers which PrimeQ incorrectly
> reports as prime are themselves in error. PrimeQ in Version 4.0 correctly
> reports both of them as not being prime.
Have you any idea why Mathematica Student Version 2.2.4 would do this?
Q1 = 89*11551*37159;
Q2 = 7309*321553*2828197;
PrimeQ[Q1]
PrimeQ[Q2]
FactorInteger[Q1]
FactorInteger[Q2]
=True
=True
={{38200901201, 1}}
={{6646915915638769, 1}}
What's so "magical" about these numbers? The notebook where I discovered
these peculiar numbers has this comment near the top:
Developed for MA 408 at Michigan Technological University
by S.W. Graham March 1995
I might try to contact the author to see what he knows.
Ps. After years of delay, I expect to upgrade to Version 4 sometime in the
next week-or-two. Hurrah!
Cheers,
Greg