20160929, 20:36  #12 
"Mark"
Apr 2003
Between here and the
6736_{10} Posts 
That is what I'm doing. It is a lot of rework. That is why I've asked for help. I have no idea when I'll be finished. I think I can finish all types to n=100000 by the end of the year, but that depends upon how many of my coworkers help. As for above n=100000, that is more difficult to gauge. Type 7 and 23 have been tested much further than other types, so it means a lot more time will be dedicated to sieving and testing. Fortunately I have sieved about half of the types 3 to 25 to appropriate depths, but will complete sieving all others (minus types 7 and 23) before I start testing the ranges. Type 7 will be absolutely terrible, so I've sent an email to Rene Dohmen hoping that he kept residues for type 7.
Last fiddled with by rogue on 20161014 at 22:00 
20161002, 15:20  #13  
"Mark"
Apr 2003
Between here and the
1101001010000_{2} Posts 
Quote:
After much consideration, I have come to the conclusion that some users were running old copies of pfgw or maybe even primeform. It is a fact that older versions of pfgw/primeform had bugs that resulted in primes being found composite. I've seen that on the other projects where I have reprocessed old ranges (generalized Cullen and Woodall). Any results prior my taking ownership (circle 2009) are likely suspect and most of the oldest work was done prior to that time. Last fiddled with by rogue on 20161014 at 22:00 

20161014, 12:37  #14 
I moo ablest echo power!
May 2013
2^{2}×11×41 Posts 
Type 16 has been tested up to n=210000.
The following PRPs were found: Code:
102354!16+1 116340!161 116682!16+1 116942!16+1 118266!16+1 123066!161 126166!16+1 130200!161 145852!16+1 152818!161 166316!16+1 167328!161 195388!161 204430!16+1 Last fiddled with by rogue on 20161014 at 22:01 
20161014, 13:09  #15 
"Mark"
Apr 2003
Between here and the
1101001010000_{2} Posts 
Thank you!
Although your results match known results for ranges known to be searched, you did find one unknown prime with 195388!161. That was beyond the known search range. Are you still planning on searching 24 and 25? 
20161014, 13:59  #16 
"Forget I exist"
Jul 2009
Dumbassville
2^{4}×3×5^{2}×7 Posts 
with k=1 b= N%K; n=N\K; where \ is the floor of division and c, this is based on the fact that a multifactorial(N,K) is which when taken mod K are all the same value so form a power under modular arithmetic mod K. so mod K these values form the same as k*b^n+c.
Last fiddled with by science_man_88 on 20161014 at 14:15 
20161014, 15:37  #17 
I moo ablest echo power!
May 2013
2^{2}·11·41 Posts 
Yes indeed. I've got type 24 running now and am currently at n=~188,000. Once that's done (at n=300,000, if I recall correctly), I'll get type 25 finished up.
Last fiddled with by rogue on 20161014 at 22:01 
20161014, 16:25  #18  
"Mark"
Apr 2003
Between here and the
2^{4}×421 Posts 
Quote:


20161014, 16:32  #19 
"Mark"
Apr 2003
Between here and the
2^{4}×421 Posts 
The entire range for !2 is now retested to 100,000. 76190!21 is a new prime that was missed by previous searches. I've been waiting to get to a milestone before posting the new search page. If I'm lucky, it will be reached this weekend.

20161014, 17:29  #20 
"Forget I exist"
Jul 2009
Dumbassville
10000011010000_{2} Posts 
I'm probably dense but I figured I'd mention it. also we know for example from this that mod 7 6^142+1 is congruent to 1000!7+1. we can use this and maybe a few other things ( like what the multiple of 7 is between them) to figure out. I guess I was mostly thinking of eliminating c values so I guess I'm just too stupid.

20161014, 18:27  #21  
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,941 Posts 
Quote:
I take it that you are referring to what Davis calls "types", i.e. how many numbers are skipped in a product series. 

20161014, 18:57  #22  
"Mark"
Apr 2003
Between here and the
1101001010000_{2} Posts 
Quote:
Outside of a few comments, I have make that change so you will see some posts have been edited. Last fiddled with by rogue on 20161014 at 22:02 Reason: Change "type" to "base" where appropriate 

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