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Old 2018-05-15, 19:42   #1
lycorn
 
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Default W T F(actor)...

It popped up this afternoon (check the Recent Cleared Report):

Gsv Manual testing 5140403 F 2018-05-15 15:39 0.3 0.0000 Factor: 10280807 / TF: 10-20

How come it had been missed?
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Old 2018-05-15, 19:50   #2
GP2
 
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It's a genuine factor.

However Mersenne.ca has date of discovery = blank, so it must have been known. Strange.

Edit:
This factor shows up in earlier snapshots of the list of factors. So this was simply a failure of the duplication suppression check, not a new discovery.

PS,
10280807 is 24 bits, so how could it show up in TF 10–20 ?

Last fiddled with by GP2 on 2018-05-15 at 20:12
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Old 2018-05-15, 20:37   #3
lycorn
 
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10280807 * 1028080601 = 10569498239325007, a 53-bit factor that pops up imediately when you run P-1 on M5140403. So may be this was the first time that 10280807 was reported "on his own right", therefore being accepted by the server.
In any case it doesn´t explain why the TF effort was recorded as TF 10-20.
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Old 2018-05-15, 21:07   #4
ATH
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The first PRP CF run from 2017-09-20 was run on 3 known factors, so it was known back in September.
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Old 2018-05-15, 21:13   #5
chalsall
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Quote:
Originally Posted by ATH View Post
The first PRP CF run from 2017-09-20 was run on 3 known factors, so it was known back in September.
Just wondering... Why are we so consternated about this factor?
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Old 2018-05-15, 21:28   #6
ATH
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Quote:
Originally Posted by chalsall View Post
Just wondering... Why are we so consternated about this factor?
Because a factor in 5M range with k=1 was reported found today in 2018, when it should have been found in 1996-1997 ?

Last fiddled with by ATH on 2018-05-15 at 21:29
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Old 2018-05-15, 21:37   #7
chalsall
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Quote:
Originally Posted by ATH View Post
Because a factor in 5M range with k=1 was reported found today in 2018, when it should have been found in 1996-1997 ?
OK. Perhaps the software way back then wasn't as good is it is now.

A few days of GPU effort will settle this once and for all....
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Old 2018-05-15, 23:23   #8
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Quote:
Originally Posted by chalsall View Post
OK. Perhaps the software way back then wasn't as good is it is now.
This factor was already known to Primenet in 2016, and no doubt much, much, much earlier.

It can't be a software problem. This factor has k=1, it's literally the very first iteration of TF.

Usually when a known factor is re-reported, it is filtered out. But sometimes for some reason, the filtering fails and the known factor appears again in the History. I recall this sort of thing happening before, but can't think of any concrete examples offhand.
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