What a (TF) factor!!...

lycorn · 2013-01-11, 14:14

Man, is this real?

From the Primenet Progress Report (Cleared exponents):

dbaugh Manual testing 2268941 F Jan 10 2013 9:11PM 0.0 7265.6046 79710277416868001845009

The figures seem correct. That´s a ~76bit factor for a 2.2M exponent. But... are you really TFing exponents so small this high, or was it just a lucky strike?

axn · 2013-01-11, 15:10

How did you determine that this was TF? More probable is ECM. How does an ECM factor report look like?

bcp19 · 2013-01-11, 18:51

Quote:

Originally Posted by axn

How did you determine that this was TF? More probable is ECM. How does an ECM factor report look like?

It does say Manual Testing... how many people run a manual ecm program? Either way, doubtful TF... 3,557 days, poss P-1? 10.4 days.

TObject · 2013-01-11, 20:42

k = 17565524492895144 = 2^3 * 3^2 * 121661 * 2005290257

lycorn · 2013-01-11, 20:47

Quote:

Originally Posted by axn

How did you determine that this was TF? More probable is ECM. How does an ECM factor report look like?

The amount of credit given matches the one expected for TFing a 2.2M exponent to ~76 bits (the length of the factor is 76.077 bits).
Moreover, factors found through TF are identified by the server with an "F", which is the current case. ECM factors are identified by "F-ECM".

petrw1 · 2013-01-11, 20:54

Quote:

Originally Posted by lycorn

Man, is this real? But... are you really TFing exponents so small this high, or was it just a lucky strike?

He is.

Dubslow · 2013-01-11, 21:47

The k that TObject mentions is a feasible P-1 Brent-Suyama hit.

I find it more likely that it was an ECM hit that got misreported than doing TF.

dabaichi · 2013-01-11, 21:50

It is possible to be a TF result, since dbaugh once trial factored M4025501 to 77 bits without finding a factor and then found a 77.127 bits factor. In that case, it's not so clear if the factor was found using TF or ECM, but the "no factor found" results should be valid I think.

dbaugh · 2013-01-12, 06:31

I do a lot of ECM and also a lot of TF. The ECM keeps the processor busy while I use mfakto and mfaktc to do TF. I lost credit for the first several hundred exponents I LL'ed over 15 years ago when Primenet migrated. I am revisiting those exponents and others in the vicinity to re-earn that credit and more doing high TF. I also like finding small missed exponents of numbers whose history was cleared by someone finding a larger factor using ECM. I keep my own records of bit levels TFed because I cannot get this information when a factor is known. The best ones are where there is no factor known. The others are a lot of work for no credit other than my own knowledge that they have been exhaustively searched up to a high bit level. Occasionally an exponent catches my interest. At the moment I especially like ones with long histories like 1000003. I have been running a 79 to 80 TF on one machine and a 80 to 81 TF on another for the last several months of the exponent 9007753.

ixfd64 · 2013-01-12, 06:53

Now that's what I call dedication!

However, I couldn't help but mention that the effort required to factor M9007753 to 81 bits is approximately equivalent to TF'ing 1,000 exponents in the 60M range from 70 to 73 bits. The latter would be much more beneficial to GIMPS. Heck, even searching for a factor of MM127 would be greatly welcomed.

dbaugh · 2013-01-12, 07:00

I split my efforts between satisfying my narrow interests and helping the larger project. If someone finds a factor of 9007753 by any means, I pledge to drop it and work on taking 1,000 60M exponents from 71 to 73 instead. 4025501 factoring method is muddied because although I reported my TF result, Primenet recorded it as an ECM result. I contacted George with all the details and he resubmitted it for me as TF.

2013-01-11, 14:14	#1
lycorn "GIMFS" Sep 2002 Oeiras, Portugal 2⁹×3 Posts	What a (TF) factor!!... Man, is this real? From the Primenet Progress Report (Cleared exponents): dbaugh Manual testing 2268941 F Jan 10 2013 9:11PM 0.0 7265.6046 79710277416868001845009 The figures seem correct. That´s a ~76bit factor for a 2.2M exponent. But... are you really TFing exponents so small this high, or was it just a lucky strike?

2013-01-11, 21:50	#8
dabaichi Sep 2011 2²×23 Posts	It is possible to be a TF result, since dbaugh once trial factored M4025501 to 77 bits without finding a factor and then found a 77.127 bits factor. In that case, it's not so clear if the factor was found using TF or ECM, but the "no factor found" results should be valid I think. Last fiddled with by dabaichi on 2013-01-11 at 21:52

2013-01-12, 06:53	#10
ixfd64 Bemusing Prompter "Danny" Dec 2002 California 2·3²·137 Posts	Now that's what I call dedication! However, I couldn't help but mention that the effort required to factor M9007753 to 81 bits is approximately equivalent to TF'ing 1,000 exponents in the 60M range from 70 to 73 bits. The latter would be much more beneficial to GIMPS. Heck, even searching for a factor of MM127 would be greatly welcomed. Last fiddled with by ixfd64 on 2013-01-12 at 07:01

2013-01-12, 07:00	#11
dbaugh Aug 2005 11² Posts	I split my efforts between satisfying my narrow interests and helping the larger project. If someone finds a factor of 9007753 by any means, I pledge to drop it and work on taking 1,000 60M exponents from 71 to 73 instead. 4025501 factoring method is muddied because although I reported my TF result, Primenet recorded it as an ECM result. I contacted George with all the details and he resubmitted it for me as TF. Last fiddled with by dbaugh on 2013-01-12 at 07:08 Reason: more info

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2013-01-11, 15:10	#2
axn Jun 2003 23·233 Posts	How did you determine that this was TF? More probable is ECM. How does an ECM factor report look like?

2013-01-11, 20:42	#4
TObject Feb 2012 3⁴·5 Posts	k = 17565524492895144 = 2^3 * 3^2 * 121661 * 2005290257

2013-01-11, 21:47	#7
Dubslow Basketry That Evening! "Bunslow the Bold" Jun 2011 40<A<43 -89<O<-88 3×29×83 Posts	The k that TObject mentions is a feasible P-1 Brent-Suyama hit. I find it more likely that it was an ECM hit that got misreported than doing TF.

2013-01-12, 06:31	#9
dbaugh Aug 2005 171₈ Posts	I do a lot of ECM and also a lot of TF. The ECM keeps the processor busy while I use mfakto and mfaktc to do TF. I lost credit for the first several hundred exponents I LL'ed over 15 years ago when Primenet migrated. I am revisiting those exponents and others in the vicinity to re-earn that credit and more doing high TF. I also like finding small missed exponents of numbers whose history was cleared by someone finding a larger factor using ECM. I keep my own records of bit levels TFed because I cannot get this information when a factor is known. The best ones are where there is no factor known. The others are a lot of work for no credit other than my own knowledge that they have been exhaustively searched up to a high bit level. Occasionally an exponent catches my interest. At the moment I especially like ones with long histories like 1000003. I have been running a 79 to 80 TF on one machine and a 80 to 81 TF on another for the last several months of the exponent 9007753.