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 2017-02-01, 13:34 #67 sweety439   Nov 2016 2,819 Posts Found an additional exclusion: Riesel k=12: base 307 has a covering set of [5, 11, 29] Thus, there are only 6 bases remain for Riesel k=12: 263, 593, 615, 717, 912, 978. Last fiddled with by sweety439 on 2017-02-01 at 13:38
 2017-02-01, 15:43 #68 sweety439   Nov 2016 2,819 Posts Also, for the "number of remaining k's" column of the text files for the remain bases, why 7*1004^n+1 and 10*1004^n+1 lists 3k, but 2*1004^n+1 lists 1k? As you say, S1004 should list 3k since k=2, 7 and 10 remain for that same base, like the example for S593, all 4*593^n+1, 8*593^n+1 and 12*593^n+1 list 3k since k=4, 8 and 12 remain for that same base, and the example for S824, both 5*824^n+1 and 8*824^n+1 lists 2k since k=5 and 8 remain for that same base, but why for S230, 12*230^n+1 lists 2k but 4*230^n+1 lists 1k? S230 should list 2k since k=4 and 12 remain for that same base. Last fiddled with by sweety439 on 2017-02-01 at 16:08
 2017-02-01, 22:24 #69 gd_barnes     May 2007 Kansas; USA 3·3,449 Posts My files have been fixed on my machine. Whenever I post them again, you will see the corrections.
2017-02-09, 01:39   #70
LaurV
Romulan Interpreter

Jun 2011
Thailand

2×3×5×313 Posts

Quote:
 Originally Posted by gd_barnes Great thanks! I keep my files updated with all primes found for these from everyone. I will note that one.
One more, turned out by LLR this morning:

2*522^62288-1 is prime! (169279 decimal digits, P = 29) Time : 768.095 sec.

And out of your interest range, but yet ok for our sweety-tweety (see the thread I posted yesterday about cllr bug),

2*1487^36432-1 is prime! (115574 decimal digits, P = 9) Time : 420.446 sec.

Last fiddled with by LaurV on 2017-02-09 at 02:14

 2017-02-09, 15:49 #71 sweety439   Nov 2016 281910 Posts There is a research for k=2 and some Sierpinski/Riesel bases (including some bases b>1030): http://mersenneforum.org/showthread.php?t=6918
2017-03-10, 19:10   #72
sweety439

Nov 2016

2,819 Posts

Quote:
 Originally Posted by gd_barnes I have now searched k=11 and 12 for all bases <= 1030. Therefore all k=2 thru 12 for all bases <= 1030 have been completed. All k=2 thru 7 have been searched to n=25K for all bases and k=8 thru k=12 have been searched to n=5K for all bases. Attached are all primes for n<=5K found by my effort, n>5K found by CRUS, and bases remaining for each k. There have been some updates for k=2 thru 10 so all of k=2 thru 12 are included. Below are all exclusions including bases with trivial factors, algebraic factors, and covering sets for k=11 and 12. Exclusions for k<=10 were previously posted. Code: Riesel k=11: b==(1 mod 2) has a factor of 2 b==(1 mod 5) has a factor of 5 b==(14 mod 15) has a covering set of [3, 5] Riesel k=12: b==(1 mod 11) has a factor of 11 b==(142 mod 143) has a covering set of [11, 13] base 307 has a covering set of [5, 11, 29] base 901 has a covering set of [7, 11, 13, 19] Sierp k=11: b==(1 mod 2) has a factor of 2 b==(1 mod 3) has a factor of 3 b==(14 mod 15) has a covering set of [3, 5] Sierp k=12: b==(1 mod 13) has a factor of 13 b==(142 mod 143) has a covering set of [11, 13] bases 562, 828, and 900 have a covering set of [7, 13, 19] base 563 has a covering set of [5, 7, 13, 19, 29] base 597 has a covering set of [5, 13, 29] bases 296 and 901 have a covering set of [7, 11, 13, 19] base 12 is a GFN with no known prime I am done with this effort. As the k's get higher, the exclusions get much more complex. Many of the bases for k>=8 are only searched to n=5K. That would be a good starting point for people to do some additional searching if they are interested in this effort.
@Gary, your text file for n > 5K for Riesel k=10 is not right, 10*992^5443-1 is not prime, it is divisible by 7.

2017-03-10, 19:26   #73
MisterBitcoin

"Nuri, the dragon :P"
Jul 2016
Good old Germany

2·13·31 Posts

Quote:
 Originally Posted by sweety439 @Gary, your text file for n > 5K for Riesel k=10 is not right, 10*992^5443-1 is not prime, it is divisible by 7.
Code:
Primality testing 10*992^5443-1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Factored: 13
composite
10*992^5443-1 is composite (5.8175s+0.0003s)

 2017-03-10, 21:10 #74 gd_barnes     May 2007 Kansas; USA 3·3,449 Posts OK thanks. The prime is 10*992^5433-1. There was a typo in my file. I have corrected it on my machine.
 2017-03-23, 05:31 #75 gd_barnes     May 2007 Kansas; USA 101000011010112 Posts I have updated the file links in post 62 here with the most recent corrections and updates.
2017-08-16, 17:58   #76
sweety439

Nov 2016

2,819 Posts

I am now reserving 2*801^n+1, 7*1004^n+1, 10*449^n+1 and 12*312^n+1 and found that 10*449^18506+1 is prime. (2*801^n+1 is currently at n=26600, 7*1004^n+1 is currently at n=28374, and 12*312^n+1 is currently at n=12394, all no prime found)

This is the result text file for 10*449^n+1.
Attached Files
 S449 k=10 result.txt (59.8 KB, 76 views)

 2017-08-16, 22:27 #77 gd_barnes     May 2007 Kansas; USA 1034710 Posts I have updated the files in post #62.