Quote:
Originally Posted by kar_bon
something like this:
call:
pfgw tc q"1468*11^26258+1"
output:
PFGW Version 20031222.Win_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4]
Primality testing 1468*11^26258+1 [N1/N+1, BrillhartLehmerSelfridge]
Running N1 test using base 2
Running N1 test using base 3
Running N+1 test using discriminant 23, base 1+sqrt(23)
Calling N1 BLS with factored part 100.00% and helper 0.02% (300.02% proof)
1468*11^26258+1 is prime! (813.9536s+0.1133s)
karsten

Hi Karsten,
Thanks for the feedback. I tried Axn1/Rogue's suggestion of using the tm switch along with the f0 switch and it speeded up the search on your prime by nearly 10 times!! Apparently the f0 switch causes it to not do any trial factoring, which would certainly be unneccesary for a probable prime. tc apparently does both a +1 and 1 test so it also does more testing than is needed. tm does just what you need here...it only does a 1 test, which is what is needed for a +1 probable prime. Here is the output:
Primality testing 1468*11^26258+1 [N1, BrillhartLehmerSelfridge]
Running N1 test using base 2
Calling BrillhartLehmerSelfridge with factored part 99.99%
1468*11^26258+1 is prime! (83.0808s+0.0065s)
The input to PFGW was: "pfgw tm f0 q1468*11^26258+1"
Particulars of the test:
It was run on a 1.66 Ghz Dell Core duo laptop. (It seems to run about as fast as a 3 Ghz P4.)
My version of PFGW does not accept the quotes around the equation.
Per the README file, I am using PFGW v1.2 Release (January 30, 2005). I downloaded it 23 months ago.
I hope this saves you a little time too!
It did me...I needed to test a much larger prime for base 17 that took almost 6 times as long as the one you tested, i.e. 92*17^51311+1, which took 476.1328s+0.0087s.
Thanks Rogue, Axn1, and Karsten for helping!
Gary