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 2018-07-28, 12:37 #694 MisterBitcoin     "Nuri, the dragon :P" Jul 2016 Good old Germany 14508 Posts I have started YAFU on p^11-1 with digit size 112. I dont have an exact number (yet); but it´s about 940 numbers. Most of them seem to have small factors, which should speed thinks up a bit. I can also take other numbers (e.g. p^19-1 (about ~1000 number with 112 digits)) after I´m finished with 112 digits. One number takes about 6200 seconds NFS plus 2150 seconds for ECM. So far I had bad luck; 4 out of 5 had to be done with NFS, the last had an 26 digits factor. Co-Factor factored with SIQS. I have no idea how long it will take, with ~6-8 numbers/day it will take ~130 days.
2018-07-28, 13:11   #695
R. Gerbicz

"Robert Gerbicz"
Oct 2005
Hungary

5C516 Posts

Quote:
 Originally Posted by MisterBitcoin I have started YAFU on p^11-1 with digit size 112. I dont have an exact number (yet); but it´s about 940 numbers.
Just interestingly (for amateurs and experts) what SNFS polynom are you using for these?

2018-07-28, 14:23   #696
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

25·151 Posts

Quote:
 Originally Posted by MisterBitcoin One number takes about 6200 seconds NFS plus 2150 seconds for ECM. So far I had bad luck; 4 out of 5 had to be done with NFS,
I'm pretty sure you'll get more finished per day if you cut your ECM effort in half.

2018-07-28, 15:51   #697
MisterBitcoin

"Nuri, the dragon :P"
Jul 2016
Good old Germany

11001010002 Posts

Quote:
 Originally Posted by R. Gerbicz Just interestingly (for amateurs and experts) what SNFS polynom are you using for these?

I´m using the polys found by YAFU. They have scores about e 8.415e-010.
YAFU´s poly search runs about 14 Minutes; while factmsieve.py only searches for ~3 minutes.
BUT: Booth gave me similar score values.

The poly instructions I got from RichD doesn´t seem to work. (probably due to "layer 8" problem ) The poly I got from RichD for that C118 needed only 2,4M Relations; the msieve/Yafu polys need 7,65M Relations for lattice sieving. Looks like there is the problem.
Cutting pretest effort will help for sure.

2018-07-28, 18:27   #698
R. Gerbicz

"Robert Gerbicz"
Oct 2005
Hungary

7×211 Posts

Quote:
 Originally Posted by MisterBitcoin I´m using the polys found by YAFU. They have scores about e 8.415e-010.
If the unfactored part is still "large" then doing this with Gnfs is a major overshoot, since these are
simply special numbers.
Asked this because when you check out such a number, say:
http://www.factordb.com/index.php?qu...844986229-1%29
(the given number is not interesting, just random)
and when you click on more information then there is an available option to get
Code:
Auto-generated SNFS-Polynominal available!
you could think that it is optimal, but it is very far from that, lets see:

Code:
n=(p^11-1)/(p-1);

f(x)=p*x^5-1;
m=p*p;
f(m)%n
so it is used a degree 5 polynom, but not used the known factor (p-1).
It was totally unable to recognize that it is a reciprocial polynomial, and we can get:

Code:
g(y)=y^5+y^4-4*y^3-3*y^2+3*y+1;
M=lift(Mod(p+1/p,n));
g(M)%n

? ? ? ? %25 = 0
? ? ? ? ? %28 = 0
(so both polynomial is valid.)

After this writing searched the web, and found this:
http://www.mersennewiki.org/index.ph...mial_Selection
explaining the same thing.

 2018-07-30, 17:32 #699 Brownfox     Dec 2017 26 Posts All most wanted numbers with SNFS difficulty below 180 digits now done. Now working on 6217^47-1 and 1091^59-1 As a matter of interest, is there any sort of target or score to work towards for the OPN bounds proofs? How many factor-weights might we need to allow the proof that there is no OPN with less than 2100 digits, for example? Thanks Steve
2018-08-02, 08:50   #700
henryzz
Just call me Henry

"David"
Sep 2007
Cambridge (GMT/BST)

587610 Posts

Quote:
 Originally Posted by Brownfox All most wanted numbers with SNFS difficulty below 180 digits now done. Now working on 6217^47-1 and 1091^59-1 As a matter of interest, is there any sort of target or score to work towards for the OPN bounds proofs? How many factor-weights might we need to allow the proof that there is no OPN with less than 2100 digits, for example? Thanks Steve
I believe it is proven upto 2100 digits. The effort here is to reduce the difficulty to prove that and larger.

2018-08-10, 12:06   #701
MisterBitcoin

"Nuri, the dragon :P"
Jul 2016
Good old Germany

14508 Posts

Quote:
 Originally Posted by MisterBitcoin I have started YAFU on p^11-1 with digit size 112. I dont have an exact number (yet); but it´s about 940 numbers. Most of them seem to have small factors, which should speed thinks up a bit. I can also take other numbers (e.g. p^19-1 (about ~1000 number with 112 digits)) after I´m finished with 112 digits. One number takes about 6200 seconds NFS plus 2150 seconds for ECM. So far I had bad luck; 4 out of 5 had to be done with NFS, the last had an 26 digits factor. Co-Factor factored with SIQS. I have no idea how long it will take, with ~6-8 numbers/day it will take ~130 days.

Quick notice:
I have stopped this effort and moved the processing power on somethink more usefull.

Soon I´ll have 4 numbers ready for SNFS with size 165 digits; they all passed pretest t40; excluding one that also survived 6600 curves@43M.

These numbers have the form p^11-1; let me know if I should post them here or elswhere.

I can also do any other form, send me an file with numbers that need pretest and suggested deeph and I´ll do them.

 2018-08-10, 14:46 #702 MisterBitcoin     "Nuri, the dragon :P" Jul 2016 Good old Germany 80810 Posts It´s down to three numbers. (165 digits; form p^11-1) These two reached t40: http://www.factordb.com/index.php?id...00001076092952 http://www.factordb.com/index.php?id...00001076093749 This reached t50: http://www.factordb.com/index.php?id...00001076094174 I´m willing to do ECM pretests for any digit size <1200 digits from this project. Just send me the numbers via PM.
2018-08-10, 17:40   #703
RichD

Sep 2008
Kansas

3,361 Posts

Quote:
 Originally Posted by MisterBitcoin It´s down to three numbers. (165 digits; form p^11-1) These two reached t40: http://www.factordb.com/index.php?id...00001076092952 http://www.factordb.com/index.php?id...00001076093749 This reached t50: http://www.factordb.com/index.php?id...00001076094174
I'll take these three. More or less to finish them off so the ECM effort is not lost and possibly duplicated.

 2018-08-12, 02:06 #704 RichD     Sep 2008 Kansas 3,361 Posts MWRB file Reserving the following numbers from the MWRB file. Code: 1103^61-1 1129^61-1 1249^61-1 1783^61-1 1867^61-1

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