Didn't even find a useless factor of an uninteresting number! Take that!

storflyt32 · 2014-06-15, 03:23

10^444031*9-1 has a known factor 66666323.

Apparently there is a factor 114851129 of (10^444031*9-1)/66666323 as well.

It took quite a bit of time finding this small factor using Yafu's ECM command and for now I did not redirect the output to any file.

Therefore the whole process including the comparison of the numbers became more or less manual between three different DOS window boxes.

Batalov · 2014-06-15, 04:37

It takes only a few seconds to find by this (very slow) script:

Code:

> gp -q
? p=66666321;
? while(1,p=nextprime(p+1);if(Mod(10,p)^444031*9==1, print(p)))
66666323
114851129

storflyt32 · 2014-10-08, 01:39

A question for you.

This number:

http://factordb.com/index.php?query=2%5E4096%2B1

The composite number there (a C1133) has not been factored. I know that there have been made several attempts, but for now without success.

Another number more indirectly related to this number is being found here.

http://factordb.com/index.php?query=...53262018919671

Perhaps I should rather tell you that I do have a factor for this number lying around. It is a somewhat larger factor, a P34, to be more precise.

I will need to carry out the factorization once again, because I have lost it. For now I only do have the mentioned factor available.

Batalov · 2014-10-08, 02:07

It is not related.

It is a cofactor of
(2^4096+1)/25860116183332395113497853167940236083358054\ 650286886725246241569916604094012679963198712829716480001-2
not of 2^4096+1

storflyt32 · 2014-10-12, 06:16

ans = 10906594903029791068395400811884464627409515459009973450004302442452725255227

P35 = 62611614700115894971255725399191227

P42 = 174194435892891975029270196982744708432001

bloodIce · 2014-10-12, 08:58

Very long factor(s), good catch. Do you plan to report them to mersenne.org ?

storflyt32 · 2014-10-13, 14:52

Thanks!

Anyway, I notice a problem with the Yafu factoring software.

I am having a 64-bit computer, so I am using both the 32-bits and 64-bits versions of this software.

Apparently the 32-bit version is returning the wrong co-factor number in the result. This has now become a very annoying feature and needs to be fixed as soon as possible.

Thanks again!

VBCurtis · 2014-10-13, 17:22

If you are reporting a bug, please list the YAFU version number, and the composite & result so someone else can try to reproduce it.

Batalov · 2014-10-13, 17:26

Quote:

Originally Posted by storflyt32

ans = 10906594903029791068395400811884464627409515459009973450004302442452725255227

P35 = 62611614700115894971255725399191227

P42 = 174194435892891975029270196982744708432001

What is this number, anyway?

storflyt32 · 2014-10-14, 13:10

ans = 5687625641025641025641025641025641025641025641025641025641025641025641025641

P33 = 213843479182611070647190753814939

P44 = 26597143213184949293331777384754973697286219

VictordeHolland · 2014-10-14, 23:33

I *guess* he is factoring the "smallest composite without known factors" from the factordb, those are also 76 digits.

2014-06-15, 03:23	#1
storflyt32 Feb 2013 735₈ Posts	Didn't even find a useless factor of an uninteresting number! Take that! 10^4440319-1 has a known factor 66666323. Apparently there is a factor 114851129 of (10^4440319-1)/66666323 as well. It took quite a bit of time finding this small factor using Yafu's ECM command and for now I did not redirect the output to any file. Therefore the whole process including the comparison of the numbers became more or less manual between three different DOS window boxes. Last fiddled with by storflyt32 on 2014-06-15 at 03:25 Reason: Better wording.

2014-06-15, 04:37	#2
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 3³·367 Posts	It takes only a few seconds to find by this (very slow) script: Code: > gp -q ? p=66666321; ? while(1,p=nextprime(p+1);if(Mod(10,p)^444031*9==1, print(p))) 66666323 114851129

2014-10-13, 14:52	#7
storflyt32 Feb 2013 3²×53 Posts	Thanks! Anyway, I notice a problem with the Yafu factoring software. I am having a 64-bit computer, so I am using both the 32-bits and 64-bits versions of this software. Apparently the 32-bit version is returning the wrong co-factor number in the result. This has now become a very annoying feature and needs to be fixed as soon as possible. Thanks again! Last fiddled with by storflyt32 on 2014-10-13 at 14:54

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2014-10-08, 01:39	#3
storflyt32 Feb 2013 3²·53 Posts	A question for you. This number: http://factordb.com/index.php?query=2%5E4096%2B1 The composite number there (a C1133) has not been factored. I know that there have been made several attempts, but for now without success. Another number more indirectly related to this number is being found here. http://factordb.com/index.php?query=...53262018919671 Perhaps I should rather tell you that I do have a factor for this number lying around. It is a somewhat larger factor, a P34, to be more precise. I will need to carry out the factorization once again, because I have lost it. For now I only do have the mentioned factor available.

2014-10-08, 02:07	#4
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 3³·367 Posts	It is not related. It is a cofactor of (2^4096+1)/25860116183332395113497853167940236083358054\ 650286886725246241569916604094012679963198712829716480001-2 not of 2^4096+1

2014-10-12, 06:16	#5
storflyt32 Feb 2013 3²×53 Posts	ans = 10906594903029791068395400811884464627409515459009973450004302442452725255227 P35 = 62611614700115894971255725399191227 P42 = 174194435892891975029270196982744708432001

2014-10-12, 08:58	#6
bloodIce Feb 2010 Sweden 173 Posts	Very long factor(s), good catch. Do you plan to report them to mersenne.org ?

2014-10-13, 17:22	#8
VBCurtis "Curtis" Feb 2005 Riverside, CA 5389₁₀ Posts	If you are reporting a bug, please list the YAFU version number, and the composite & result so someone else can try to reproduce it.

2014-10-14, 13:10	#10
storflyt32 Feb 2013 3²×53 Posts	ans = 5687625641025641025641025641025641025641025641025641025641025641025641025641 P33 = 213843479182611070647190753814939 P44 = 26597143213184949293331777384754973697286219

2014-10-14, 23:33	#11
VictordeHolland "Victor de Hollander" Aug 2011 the Netherlands 3²×131 Posts	I guess he is factoring the "smallest composite without known factors" from the factordb, those are also 76 digits.