alright Fermat divisors, ya can run....

ixfd64 · 2004-05-24, 22:17

...but ya can't hide.

Seriously, though... Anyone notice the huge gap between the discovery of Fermat divisors? I mean, it's been almost 7 months since the last Fermat divisor was discovered. Is the project even running?

Well, on the bright side, a longer gap can sometimes mean a bigger surprise! :)

---
*makes funny face at next poster*

ET_ · 2004-05-25, 12:40

Quote:

Originally Posted by ixfd64

...but ya can't hide.

Seriously, though... Anyone notice the huge gap between the discovery of Fermat divisors? I mean, it's been almost 7 months since the last Fermat divisor was discovered. Is the project even running?

The Project is up and running.

I received many updates from Fermat's factors searchers :-)

Luigi

philmoore · 2004-05-25, 17:14

Quite a few large Proth primes have been discovered in the past six months, but as luck would have it, none of them proved to be a Fermat number divisor. But sooner or later...

jinydu · 2004-05-26, 01:50

What is the smallest Fermat number whose primality status is unknown?

ixfd64 · 2004-05-26, 02:53

I believe it's F33.

akruppa · 2004-05-26, 05:51

It is, according to Wilfrid Keller's status page.

ewmayer · 2004-05-26, 14:29

Quote:

Originally Posted by akruppa

It is, according to Wilfrid Keller's status page.

And if anyone would know, it would be Alex. ;)

jinydu · 2004-05-27, 00:26

"Composite but no factor known m = 14, 20, 22, 24"

So there is a primality test for Fermat numbers that doesn't require finding a factor?

ixfd64 · 2004-05-27, 05:01

Well, there's Pepin's test, but the numbers quickly grow too large for it.

jinydu · 2004-05-27, 05:42

Hmm. F25 already has over 10.1M digits.

No wonder... Mersenne Numbers grow exponentially while Fermat Numbers grow "double exponentially".

2004-05-24, 22:17	#1
ixfd64 Bemusing Prompter "Danny" Dec 2002 California 2·3²·137 Posts	alright Fermat divisors, ya can run.... ...but ya can't hide. Seriously, though... Anyone notice the huge gap between the discovery of Fermat divisors? I mean, it's been almost 7 months since the last Fermat divisor was discovered. Is the project even running? Well, on the bright side, a longer gap can sometimes mean a bigger surprise! :) --- makes funny face at next poster

2004-05-27, 05:42	#10
jinydu Dec 2003 Hopefully Near M48 2×3×293 Posts	Hmm. F25 already has over 10.1M digits. No wonder... Mersenne Numbers grow exponentially while Fermat Numbers grow "double exponentially". Last fiddled with by jinydu on 2004-05-27 at 05:43

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pari gp Command divisors() ?	Godzilla	PARI/GP	30	2018-03-03 18:15
Finding all divisors kn + 1 of P(n) for various polynomials P	Drdmitry	Computer Science & Computational Number Theory	0	2014-11-28 14:51
Looking for fermat divisors, n=90-120	firejuggler	Prime Sierpinski Project	2	2012-01-10 17:14
Fermat number and Modulo for searching divisors	CyD	Factoring	4	2011-05-31 11:24
Number of divisors of n?	Citrix	Math	10	2006-02-08 04:09

2004-05-25, 17:14	#3
philmoore "Phil" Sep 2002 Tracktown, U.S.A. 2137₈ Posts	Quite a few large Proth primes have been discovered in the past six months, but as luck would have it, none of them proved to be a Fermat number divisor. But sooner or later...

2004-05-26, 01:50	#4
jinydu Dec 2003 Hopefully Near M48 2·3·293 Posts	What is the smallest Fermat number whose primality status is unknown?

2004-05-26, 02:53	#5
ixfd64 Bemusing Prompter "Danny" Dec 2002 California 2×3²×137 Posts	I believe it's F33.

2004-05-26, 05:51	#6
akruppa "Nancy" Aug 2002 Alexandria 2,467 Posts	It is, according to Wilfrid Keller's status page.

2004-05-27, 00:26	#8
jinydu Dec 2003 Hopefully Near M48 2×3×293 Posts	"Composite but no factor known m = 14, 20, 22, 24" So there is a primality test for Fermat numbers that doesn't require finding a factor?

2004-05-27, 05:01	#9
ixfd64 Bemusing Prompter "Danny" Dec 2002 California 2·3²·137 Posts	Well, there's Pepin's test, but the numbers quickly grow too large for it.