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 2021-02-28, 08:47 #485 earshot   Feb 2021 1 Posts powmod via script gives me incorrect results when it starts using Generic modular reduction. I was learning using script en scriptify and started by making a Mersenne Prime script. It first checks the candidates by powmod base 3 and when it is successful it runs a complete test. It finds all the Mersenne primes up to 607 but for p>=647 modular reduction is used and incorrect results are generated. Is this a known bug or am I doing something wrong?
 2021-04-25, 01:27 #486 paulunderwood     Sep 2002 Database er0rr 32×19×23 Posts The rep-unit function "r()" prints a lot of extranious spaces after the number. For example: Code: ./pfgw64 -f0 -od -q"r(5794777)" | wc PFGW Version 4.0.1.64BIT.20191203.x86_Dev [GWNUM 29.8] No factoring at all, not even trivial division 1 2 5794826 Last fiddled with by paulunderwood on 2021-04-25 at 01:29
 2021-04-25, 02:00 #487 ATH Einyen     Dec 2003 Denmark C7B16 Posts This works, it gives a file with 5794777 1's: Code: ./pfgw64 -f0 -od -q"r(5794777)" | tail -c +13 | head -c 5794777 > rep5794777.txt The number 13 in "tail -c +13" has to be 6 more than the number of digits in 5794777.
 2021-10-18, 09:43 #488 Puzzle-Peter     Jun 2009 22·173 Posts help needed Dear all, Norman Luhn (Cybertronic) and I are trying to prove the following number using PFGW: (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 there is a file helper.txt which contains 520461*2^55931+1 2584831267 The command we are using is pfgw -tc -l -hhelper.txt I tried the following PFGW versions: Linux Version 3.8.3 64bit Linux Version 3.7.8 64bit Windows 4.0.0/1 64bit (Help - About says 4.0.0, onscreen it says 4.0.1) Windows 3.6.5 32bit and 64bit All tests run on Intel CPUs They all gave me "is prime" with an output that looks like this: Code: Primality testing (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 [N-1/N+1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 5 Running N-1 test using base 13 Running N+1 test using discriminant 29, base 3+sqrt(29) Calling N-1 BLS with factored part 33.33% and helper 0.02% (100.01% proof) (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 is prime! (236.0713s+0.0011s) Norman can't reproduce the primality on his AMD machines, he only gets Fermat and Lucas - PRP. We tried to determine what's going on but we can't pinpoint the issue. I have no AMD, he has no Intel machines. Could some people please try and post PFG Version, CPU, OS and result? this test only takes a few minutes to run. Thanks a lot Peter
 2021-10-18, 09:57 #489 Cybertronic     Jan 2007 Germany 2×11×19 Posts Additions: I get also on a Laptop SONY Vaio Intel processor "Fermat-Lucas-PRP" PFGW Versions: Very old up to V4.0 32/64bit OS Windows 10 / Windows 7 command line pfgw2 -tc -hxyz cs Output: OS Windows 10 , Ryzen 7 1700 3GHz Z:\PFGW>pfgw2 -tc -hxyz cs PFGW Version 1.2.0 for Windows [FFT v23.8] ***WARNING! file cs may have already been fully processed. Primality testing (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 [N-1/N+1, Brillhart-Lehmer-Selfridg Reading factors from helper file xyz Running N-1 test using base 5 Running N-1 test using base 13 Running N+1 test using discriminant 29, base 3+sqrt(29) Calling N+1 BLS with factored part 0.02% and helper 0.00% (0.07% proof) (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 is Fermat and Lucas PRP! (903.1017s+0.0100s) xyz: numbers 520461*2^55931+1 2584831267
 2021-10-18, 10:18 #490 kruoli     "Oliver" Sep 2017 Porta Westfalica, DE 7·109 Posts Code: Puzzle-Peter: Calling N-1 BLS with factored part 33.33% and helper 0.02% (100.01% proof) Cybertronic: Calling N+1 BLS with factored part 0.02% and helper 0.00% (0.07% proof) The program is doing different tests; the last one is definitely the wrong "tool" for this number, so it is not able to detect the number being prime. But the question remains, why it executes a different tests here…
2021-10-18, 10:39   #491
paulunderwood

Sep 2002
Database er0rr

32×19×23 Posts

Quote:
 Originally Posted by Cybertronic xyz: numbers 520461*2^55931+1 2584831267
Does xyz contain the word "numbers"?

 2021-10-18, 10:47 #492 Cybertronic     Jan 2007 Germany 2·11·19 Posts Only this two lines 520461*2^55931+1 2584831267
 2021-10-18, 10:57 #493 paulunderwood     Sep 2002 Database er0rr 32·19·23 Posts One thing to try: rename "xyz" to "helper" and run with -hhelper
 2021-10-18, 11:00 #494 Cybertronic     Jan 2007 Germany 2·11·19 Posts Okay, I will try -hhelper Other files in use was -hhelper.txt , without success
 2021-10-18, 11:08 #495 axn     Jun 2003 5,179 Posts Code: ~/Desktop/pfgw_linux_4.0.1/distribution$./pfgw64 -tc -l -hhelper.txt input.txt PFGW Version 4.0.1.64BIT.20191203.x86_Dev [GWNUM 29.8] Output logging to file pfgw.out Primality testing (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 [N-1/N+1, Brillhart-Lehmer-Selfridge] Reading factors from helper file helper.txt Running N-1 test using base 5 Running N-1 test using base 13 Running N+1 test using discriminant 29, base 3+sqrt(29) (520461*2^55931+1)*(43439253939*(520461*2^55931-1)^2-3)+1 is prime! (294.1606s+0.0005s) ~/Desktop/pfgw_linux_4.0.1/distribution$ uname -a Linux R5 5.4.0-88-generic #99-Ubuntu SMP Thu Sep 23 17:29:00 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux ~/Desktop/pfgw_linux_4.0.1/distribution$lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 20.04.3 LTS Release: 20.04 Codename: focal ~/Desktop/pfgw_linux_4.0.1/distribution$ lscpu Model name: AMD Ryzen 5 3600 6-Core Processor

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