PFGW can't find a small factor.

Arkadiusz · 2013-02-17, 12:40

For example,
2362339121*2^1018-1 has no small factor.

mod(2362339121*2^1018-1, 17) = 0.

rogue · 2013-02-18, 00:19

Quote:

Originally Posted by Arkadiusz

For example,
2362339121*2^1018-1 has no small factor.

mod(2362339121*2^1018-1, 17) = 0.

Thanks. I will investigate.

axn · 2013-02-18, 04:01

Quote:

Originally Posted by Arkadiusz

For example,
2362339121*2^1018-1 has no small factor.

mod(2362339121*2^1018-1, 17) = 0.

What version?

Code:

PFGW Version 3.6.0.32BIT.20111222.Win_Dev [GWNUM 26.6]

2362339121*2^1018-1 has factors: 17

Batalov · 2013-02-18, 04:07

Code:

PFGW Version 3.7.2.64BIT.20130122.x86_Dev [GWNUM 27.9]
2362339121*2^1018-1 is composite: RES64: [3DE9C23DFB42D757] (0.0017s+0.0267s)
...
PFGW Version 3.7.3.32BIT.20130210.Win_Dev [GWNUM 27.8]
2362339121*2^1018-1 is composite: RES64: [3DE9C23DFB42D757] (0.0022s+0.0838s)
PFGW Version 3.7.3.64BIT.20130210.Win_Dev [GWNUM 27.8]
2362339121*2^1018-1 is composite: RES64: [3DE9C23DFB42D757] (0.0020s+0.0295s)

- probably introduced later than 3.6.0

ET_ · 2013-02-18, 07:42

What is the command line?

pfgw[32|64]{s} -q2362339121*2^1018-1

or

pfgw[32|64]{s} -t -q2362339121*2^1018-1

or

pfgw[32|64]{s} -t -f -q2362339121*2^1018-1

?

Luigi

axn · 2013-02-18, 08:25

I used -f -q (in windows command line you have to escape the ^ with ^^)

Arkadiusz · 2013-02-18, 10:23

Open WinPFGW Version 3.6.5.
PFGW Version 20130210.
pfgw -f -o input file.txt

rogue · 2013-02-18, 12:43

3.6.7 finds the factor, but 3.7.3 does not. I assume it was due to reintroduction of the tree factoring code. I'm getting help from someone much more familiar with that code.

2013-02-17, 12:40	#1
Arkadiusz Dec 2009 3³ Posts	PFGW can't find a small factor. For example, 23623391212^1018-1 has no small factor. mod(23623391212^1018-1, 17) = 0.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
PFGW 3.6.x problems on small primes	gd_barnes	Conjectures 'R Us	18	2014-07-13 11:51
Can Pollard Rho cycles be used to find a factor?	wwf	Factoring	26	2013-09-30 04:24
Fails to find very small factors.	Mr. P-1	FactorDB	6	2013-03-22 02:30
How much ECM does it take to find a given factor?	geoff	Factoring	5	2004-09-29 20:14
Where I find the best program to it factor keys? I use AMD.	chrow	Factoring	5	2004-02-19 10:15

2013-02-18, 07:42	#5
ET_ Banned "Luigi" Aug 2002 Team Italia 2·7·347 Posts	What is the command line? pfgw[32\|64]{s} -q23623391212^1018-1 or pfgw[32\|64]{s} -t -q23623391212^1018-1 or pfgw[32\|64]{s} -t -f -q2362339121*2^1018-1 ? Luigi

2013-02-18, 08:25	#6
axn Jun 2003 2×2,719 Posts	I used -f -q (in windows command line you have to escape the ^ with ^^)

2013-02-18, 10:23	#7
Arkadiusz Dec 2009 3³ Posts	Open WinPFGW Version 3.6.5. PFGW Version 20130210. pfgw -f -o input file.txt

2013-02-18, 12:43	#8
rogue "Mark" Apr 2003 Between here and the 19×367 Posts	3.6.7 finds the factor, but 3.7.3 does not. I assume it was due to reintroduction of the tree factoring code. I'm getting help from someone much more familiar with that code.