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Old 2007-12-15, 09:54   #2
gd_barnes's Avatar
May 2007
Kansas; USA

5·2,029 Posts
Default Guidelines on doing searches

Below are the suggested guidelines for doing a prime-search effort for the conjectures. All instructions here are the fastest known ways that I am aware of but some of you may not want to take extra steps for speed.


1. If you are sieving more than one k for n > 2500:
a. Run srsieve with the -a parameter up to P=100M.
b. Run sr2sieve up to an appropriate value.
c. Run srfile with the -G (sorted by n) or -g (sorted by k) parameter to remove factors and create input for LLR or PFGW.

2. If you are sieving 1 or 2 k's for n > 2500:
a. Run srsieve with the -g paramater up to P=100M.
b. Run 1 or 2 instances of sr1sieve up to an appropriate value (1 instance for each k).

3. If you are searching any # of k's for n <= 2500, no sieving is needed. A PFGW script using trial factoring is by far the fastest way to go. If you are testing a new base or a new k-range for a previously searched base, see important notes about starting a new base below.

Primality testing:

1. For bases that are powers of 2:
a. Run LLR with the sieve file as input and a file name of prime.txt as output.
b. Two files will be created: prime.txt and lresults.txt. Check for and post any primes found and send me the results file.

2. For bases that are not powers of 2:
a. Run PFGW with the sieve file as input using the -f0 and -l switches in order to do PRP tests on the entire range of n. 2 or 3 files will be created: Primes will be in pfgw-prime.log, probable primes (PRP's) will be in pfgw.log, and the results will be in pfgw.out. IMPORTANT: If you have to stop PFGW in the middle of testing, it will not remember k's that it has found primes for and will begin searching them again when you restart. See instructions in the next post under #2 (referencing running LLR) for running srfile to remove k's with primes before restarting.
b. Run PFGW to prove primality of the pfgw.log output from a. using the -f0 switch and (-t switch for the Sierp side -OR- -tp switch for the Riesel side). Once all have been proven, as with LLR, please post primes found and send me the results file.
[See important notes below if starting a new k-range or starting a new base. You'll need to use the PFGW script for new bases as instead of a sieve file as input to PFGW.]

Below are IMPORTANT notes on starting from scratch on a NEW BASE. Even with the automated script, if you're new to CRUS, I'd suggest getting with me or one of our regular searchers first. Some of the exceptions can get quite tricky.

1. As shown in the 1st post here, please use the link to the script for starting new bases as input to PFGW.

2. Review the web pages for algebraic factors such as squared k's on Riesels or cubed k's on Riesels and Sierpinski's for removal at the end of the search. Worse than searching for a multiple of the base that might be a duplicate effort would be to search a k that was proven composite for all n without realizing it ahead of time.

3. If you have to stop PFGW in the middle of the search and have to restart it, it will not remember where it left off (because it is running a script). A change to the min_k in the script will be needed before restarting.

4. Please send me the pl_MOB, pl_prime, and pl_remain output files from the new bases script. A results file is not necessary. Also, if it is an even Sierp base, please send me the pl_GFN file. If any of the files would be too large, let me know. For large-conjectured bases such as 3, 7, and 15, I will probably suggest just sending primes for n>1000 while running primes up to n=1000 myself because the files are too large to send around. For ultimate proof in the mathematical world, we'll need a central repository of the primes found for each k. I'll post an Email later on to send them to.

Good luck and may the prime-searching God's be with us all!


Last fiddled with by gd_barnes on 2010-01-21 at 21:43 Reason: more modern updates
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