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Old 2008-03-16, 14:57   #1
Kosmaj
 
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Default Benson's prime search

Mr. Benson (L80, L503) is obviously searching for Riesel primes (k*2^n-1) in the "-" vicinity of respective FFT jumps (in LLR) for small k's (most likely k<100). After reporting several primes for k/n pairs using 56k FFT, he has now moved to 64k and he just reported a k=21 prime at 1170k (the FFT jump occurs at 1181k). If you are testing a k that may be affected you may consider taking some steps to counter his advance.

I'd like to invite Mr. Benson to coordinate his search with us. I have said this before but I'd like to repeat, that besides testing k<300 by ourselves we are also trying to coordinate search with others with no obligations, i.e., they can report their primes without reference to RPS in their Top-5000 prover's code. A number of people are already doing it, like Justin of 12121, David Broadhurst, and Gryphon. Mr Benson is free to reserve whatever k/n ranges he wants. Searching a little bit here and a little bit there will result in many gaps and fragmented ranges that will be no fun to connect later.
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Old 2008-03-16, 19:13   #2
Cruelty
 
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I would also welcome some coordination with Mr. Benson, as I don't really want to duplicate any work that anyone has done so far...
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Old 2008-03-16, 19:16   #3
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Is there any way to contact him? His e-mail address at the primepages is unpublished.
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Old 2008-03-18, 21:37   #4
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He found a second megabit prime this month, it seems he tests some k<100 and is at the moment roughly at n=1175000 with very fast progress.
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Old 2008-03-19, 09:33   #5
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it seems that he is using our progress reports however does not share his...
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Old 2008-03-19, 13:50   #6
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Quote:
Originally Posted by Cruelty View Post
it seems that he is using our progress reports however does not share his...
I don't know about this, in any case he either does not realize that others search the same ranges (that's unlikely) or he knows it and it doesn't matter to him.

In both cases, it's no problem for me to see this as a race (with k=17 I am sure to be ahead of him), but it's not fine for all who want a more complete search (I would prefer this, too).
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Old 2008-03-20, 07:14   #7
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I've gotten "page not found" at 15k.org for the k<300 page the last 3 nights. Any idea what happened? It appears the site itself is up, but our page is missing- not the usual hiccups we get periodically.
-Curtis
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Old 2008-03-20, 07:36   #8
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I removed it for a while because, obviously, some persons are using our completon limits to their advantage while not providing any insight into their search. I'm currently setting up the page with password protecton.
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Old 2008-03-21, 02:08   #9
mdettweiler
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Quote:
Originally Posted by Kosmaj View Post
I removed it for a while because, obviously, some persons are using our completon limits to their advantage while not providing any insight into their search. I'm currently setting up the page with password protecton.
Well, even if others are using this information to our disadvantage, shoudln't this still be public information? What's the use of searching for all these primes if nobody can know about it except those who are already established with this project? (In fact, it would probably discourage new participants, since they can't even see what k's are available to reserve, and the only way to get access to that information is to first get themselves situated with the project be searching some work from the team drives, which they may or may not prefer to do.)
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Old 2008-03-21, 02:40   #10
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Quote:
Originally Posted by Kosmaj View Post
I removed it for a while because, obviously, some persons are using our completon limits to their advantage while not providing any insight into their search. I'm currently setting up the page with password protecton.
Password protection? What's next? Password protection for the RPS forum? You can run but you cannot hide. This is a slipperly slope that RPS does not want to go down. Are you going to have everyone report their search limits by PM to you? If so, then it's not really a project. It's just a fragmented effort that few will have fun with.

Karsten already has all the limits on his k<300 page. They're just a few weeks out of date but can be easily updated by looking in the forums here. I could do it myself quite accurately in < 8 hours and post everything on my own site, hosted by the very stable googlepages.

The best way to avoid people using ranges to their advantage is to follow up on dormant reservations like I have been harping on all along. Do that and you'll avoid at least some of the problems. Maybe not all but some.

The 2nd best thing to do is to reserve and search your k's quickly. Don't jack around by reserving > 20 k's at once for k < 300 like seems to be the case for serveral people here. You can't search them fast enough before they are picked off by Benson and others.

I was 'picked off' by Benson on k=61; Kosmaj was 'picked off' by Benson on k=75; both between n=900K-1M. These weren't dormant reservations but k=61 was dormant for 9 months before I finally picked it up and k=75 was being searched much too slowly. You have to make Benson work hard to pick off a prime by keeping them searched to an appropriate level at all times.

"No Prime Left Behind" is and will be 'picked off' all the time in our search ranges. We don't sweat it. Why should RPS? 'Hiding' your efforts behind passwords will drive people away and they will not be people that you want to leave.


Gary

Last fiddled with by gd_barnes on 2008-03-21 at 02:43
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Old 2008-03-21, 03:25   #11
AES
 
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Personal completion limits were posted for the benefit of those honoring the reservation system.

I see no point in making updated completion limits readily available to those that would use them to the determent of ones own efforts. It’s only a leisure activity, but a modest amount of professionalism and courtesy is not too much to expect.
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