mersenneforum.org Sierpinski/Riesel Base 5: Post Primes Here
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 2005-01-25, 22:11 #23 geoff     Mar 2003 New Zealand 115710 Posts Robert, could you make available a list of the primes you found for n <= 18468? Or if you email it to me ( geoff AT hisplace DOT co DOT nz ) I will make it available. I will keep a list of primes that make the top 5000 list in http://www.geocities.com/g_w_reynold...ki5/champs.txt, there is just one entry so far. My results: I found (a while ago) that 32518*5^47330+1 is prime. I am reserving these k: 10918, 12988, 31712. Last fiddled with by geoff on 2005-01-25 at 22:15
 2005-01-28, 06:31 #24 michaf     Jan 2005 7378 Posts Hello all, I agree with uncwilly that this project should deserve it's own private place... anyone know how to move it? In the meantime: One more down: PFGW Version 20041020.Win_Stable (v1.2 RC1c) [FFT v23.8] Primality testing 42004*5^27992+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 2 Calling Brillhart-Lehmer-Selfridge with factored part 99.98% 42004*5^27992+1 is prime! (57.0569s+0.0044s)
 2005-01-30, 12:42 #25 michaf     Jan 2005 47910 Posts Yet another one down Hi all, 4th prime on here: PFGW Version 20041020.Win_Stable (v1.2 RC1c) [FFT v23.8] Primality testing 44134*5^39614+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 7 Calling Brillhart-Lehmer-Selfridge with factored part 99.98% 44134*5^39614+1 is prime! (150.2650s+0.0062s) Cheers, Micha
 2005-01-31, 20:28 #26 ltd     Apr 2003 22·193 Posts Hi, here my newest results: 60124*5^38286+1 is prime! 60394 tested to 50166 ( i keep this reserved) 60722 tested to 49329 ( i keep this reserved) I also keep my other k reserved. Lars
 2005-02-01, 02:13 #27 geoff     Mar 2003 New Zealand 13·89 Posts The primes.txt file in http://www.geocities.com/g_w_reynolds/Sierpinski5/ contains the k,n pairs for all the primes k*5^n+1 found so far. It can be used as input to Proth.exe in file mode, or by adding 'ABC $a*5^$b+1' to the top, as input to pfgw.
 2005-02-01, 18:01 #28 robert44444uk     Jun 2003 Oxford, UK 19×103 Posts Nought This may come to nought, actually no, it will come to k+1 What am I talking about? n=0 ---> k*5^0+1= k+1 Therefore any k still remaining where k+1 is prime can be eliminated, unless that is not in the Sierpinski rule book. Looking at my original list, this would eliminate 7528 and maybe others....not got a list of primes to hand What does this group think of this wheeze? Regards Robert Smith
 2005-02-01, 21:09 #29 robert44444uk     Jun 2003 Oxford, UK 19·103 Posts n=0 Following on, now I am home: From the original list n=0 eliminates (and a number of these we have found already higher primes or prp for): 7528 15802 33358 43018 51460 81700 82486 90676 102196 105166 123406 123910 143092 152836 159706 Regards Robert Smith
2005-02-01, 22:35   #30
geoff

Mar 2003
New Zealand

13·89 Posts

Quote:
 Originally Posted by robert44444uk Therefore any k still remaining where k+1 is prime can be eliminated, unless that is not in the Sierpinski rule book.
The definitions of Sierpinski number that I have seen take n to be positive, e.g. http://mathworld.wolfram.com/Sierpin...erTheorem.html, so I think we should leave these k in the list. (If they turn out to be harder than the other k then we could reconsider :-)

2005-02-02, 14:01   #31
pcco74

Feb 2005
Pittsburgh

3 Posts

Quote:
 Originally Posted by geoff The definitions of Sierpinski number that I have seen take n to be positive, e.g. http://mathworld.wolfram.com/Sierpin...erTheorem.html, so I think we should leave these k in the list. (If they turn out to be harder than the other k then we could reconsider :-)
Yves Gallot's site also lists n as having to be greater than or equal to one. http://www.prothsearch.net/sierp.html

2005-02-02, 18:10   #32
Citrix

Jun 2003

2×7×113 Posts

Quote:
 Originally Posted by pcco74 Yves Gallot's site also lists n as having to be greater than or equal to one. http://www.prothsearch.net/sierp.html
This is for base 2 only, 5^0 should be considered too.

 2005-02-02, 19:10 #33 robert44444uk     Jun 2003 Oxford, UK 19·103 Posts Odds and evens I posted the following message on Yahoo primenumbers to see whether one of the maths bods can give an answer. I am reasonably confident we should allow n=0 http://groups.yahoo.com/group/primen.../message/16018 Regards Robert Smith

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