20221218, 16:08  #1420 
"Nuri, the dragon :P"
Jul 2016
Good old Germany
2^{3}×3×37 Posts 
Reserving R30 up to n=550K.

20221230, 17:20  #1421 
Sep 2011
Germany
EA9_{16} Posts 
R15 tested to n=600k (450600k) (010M)
2 primes found, 6 remain Results emailed  extending to 1M 
20230328, 06:06  #1422 
Sep 2011
Germany
3^{3}×139 Posts 
Reserving S10 to n=3M (23M) for SRBase

20230417, 08:10  #1423 
Sep 2011
Germany
3^{3}×139 Posts 
R15 tested to n=1M (600k1M) (010M)
1 prime found, 5 remain Results emailed  Base released 
20230429, 09:30  #1424 
Sep 2011
Germany
3^{3}×139 Posts 
S10 tested to n=3M (23M)
nothing found, 1 remain Results emailed  Base released 
20230429, 14:28  #1425 
Sep 2011
Germany
3753_{10} Posts 
Reserving R10 to n=3M (23M) for SRBase

20230622, 06:09  #1426 
"Gary"
May 2007
Overland Park, KS
12,569 Posts 
In an effort to account for all of the k's on R25 in order to create the "all k's" file on our webpage, I ran a doublecheck to n=25K. In doing so, I found that 7 primes had been missed as follows:
41562*25^99251 47238*25^88021 56016*25^97221 69330*25^90771 70344*25^82131 70680*25^89561 126114*25^154191 The files that I had were a mess. Part of the problem was that a lot of primes were pulled over from base 5. Another was that many different people were involved on it back in the early days of CRUS so primes were pulled from many sources. I had many different files with quite a few gaps, many likely as a result of primes posted in the forum here that I did not copy off to my machine, which has become a recurrent theme from our old team efforts. (My bad!) Based on the tight bunching of all but 1 of the primes, I suspect that this was more of a coordination problem than any software issues. Perhaps k=40K75K for n=8K10K was simply missed. Fortunately 4 of the k's already had larger primes. But that left the following 3 k's that were remaining at n=300K and have now been removed from our pages: 47238 56016 70680 That now leaves exactly 100 k's remaining at n=300K. Included are all primes for n>300K that were found from the SR5 effort that is now being worked on by PrimeGrid. The R25 "allks" file is now posted on the page. Thankfully the files that I have for S25 are much cleaner. Although I'm doublechecking it to n=25K now, I anticipate very few or no problems. Thanks to Mark for the very cool srbsieve program that is very effective in working on these doublechecks to as high of an nlimit as I want! Last fiddled with by gd_barnes on 20230622 at 06:12 
20230627, 06:27  #1427 
Sep 2011
Germany
EA9_{16} Posts 
R10 tested to n=3M (23M)
nothing found, 1 remain Results emailed  Base released 
20230712, 08:40  #1428  
"Gary"
May 2007
Overland Park, KS
12569_{10} Posts 
Quote:
Before posting my all k's files, I doublecheck everything to n=25K if I don't have a clear set of files, which I often haven't had on these hugeconjectured small bases. k=148458 showed as remaining at n=25K after my run of srbsieve. I then did a standalone doublecheck of myself on a different machine. Nope; still remaining. I could not find a prime for it in my files, the forum here, the CRUS pages where we have a page/file of primes n>25K for bases 3/7/15, and the top5000 site. I finally tried one last thing: I manually went through and did searches on each page in this thread for "15^". My sleuthing finally came to an end at the above post. k=148548 had been searched for n>10K instead of k=148458. 148548*15^13101+1 is definitely prime but unfortunately that doesn't help us. k=148548 already had 3 primes for n<50. Either the kvalue or a sieve file was incorrectly posted on the CRUS pages at the time or the searcher just picked it up incorrectly. So going forward: It showed as remaining at n=10K in my files so it's been effectively triplechecked to n=10K and double checked for n=10K25K. I have completed sieving for n=25K100K and am searching it. It's currently at n=40K. It's only running on one core and will be done in about a day if no prime is found. For S15, all k<=5M have been searched to n=200K. If it still remains at n=100K, I'll sieve it for n=100K200K and add more resources to it to bring it up to the other k's on the base. In the mean time, I'm holding off on updating the pages or posting the all k's file until I'm done with it. If it still remains at n=200K, it will be the smallest remaining k for S15. I've had my fun for the night. :) 

20230712, 11:32  #1429 
"Gary"
May 2007
Overland Park, KS
12,569 Posts 
That didn't last too long:
148458*15^51788+1 is prime 
20230719, 08:38  #1430 
"Gary"
May 2007
Overland Park, KS
12,569 Posts 
I was doing an accounting of all k<=10M for S7. I initially ran a doublecheck for the range to n=25K. I found some serious problems only for the k=5M10M range.
First, there were 16 missing primes as follows: Code:
5072244*7^6+1 5203866*7^4+1 5452324*7^6+1 5629252*7^6+1 5770774*7^5+1 6302236*7^4+1 6609082*7^6+1 7069908*7^5+1 8122398*7^4+1 8566504*7^6+1 8738868*7^6+1 8760604*7^5+1 9126852*7^4+1 9462126*7^4+1 9494736*7^5+1 9542640*7^5+1 Code:
5117814 5371308 5497278 5638338 5663272 5673636 5771676 6212106 6338104 6427404 6464844 6638776 6828694 6874968 7131814 7362214 7458994 7961172 8153368 8631642 8643682 8791996 9316288 9967266 For the first group of 16 missed primes, 15 of them already had primes n>25K found for them: Code:
5072244*7^137454+1 5203866*7^26944+1 5452324*7^277094+1 5629252*7^44310+1 5770774*7^66269+1 6302236*7^37531+1 6609082*7^31919+1 7069908*7^28577+1 8122398*7^26548+1 8738868*7^37910+1 8760604*7^67010+1 9126852*7^31582+1 9462126*7^66933+1 9494736*7^35275+1 9542640*7^39624+1 For the second group of k's not accounted for, to be consistent with our already tested range, all 24 k's had to be searched to n=300K or a prime was found. The following 20 primes were found for n=25K300K: Code:
5117814*7^30654+1 5371308*7^37869+1 5497278*7^166454+1 5638338*7^34308+1 5663272*7^28034+1 5771676*7^30380+1 6212106*7^30133+1 6338104*7^143570+1 6427404*7^25265+1 6464844*7^46841+1 6638776*7^59672+1 6828694*7^34298+1 6874968*7^34409+1 7131814*7^46690+1 7362214*7^112357+1 7458994*7^59314+1 7961172*7^63582+1 8153368*7^35073+1 8631642*7^39830+1 8791996*7^143761+1 That left the following 4 k's remaining at n=300K that were added to our page: Code:
5673636 8643682 9316288 9967266 4  1 = 3 k's remaining 20  15 = 5 primes n>25K Due to my concern about this, I also completed the following doublecheck: All k<10M to n=50K. All k=10M20M to n=25K. No additional problems were found (thankfully). Note that all k=10M1G to n=25K was done quite a bit later than k<=10M. It is only the smaller k's that had been searched for n>25K. As for what caused this, I can only speculate that a software issue caused the first problem. They aren't all in the range of the 40bit problem but some are. So there could have been a similar problem somewhere at the time. I also speculate that human error caused the second problem. There was a range of 11 consecutive k's for k=5M6.5M that were in between two consecutive k's previously shown on our remaining page. A range likely got missed somewhere and it didn't stick out at me enough at the time when I posted everything. But it doesn't fully explain the other k's that were more randomly dispersed throughout the range. So finally all k<=10M for S7 are accounted for. (Actually all k<=20M but I'm only showing k<=10M for now.) Last fiddled with by gd_barnes on 20230719 at 08:46 
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