Thread: Octoproths
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Old 2006-01-13, 14:11   #242
R. Gerbicz
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"Robert Gerbicz"
Oct 2005

2×7×103 Posts

Originally Posted by Greenbank
Mean time I put my Quad G5 to good use and I've completed the search ranges for all n <=48 (and 49,50 and 51 are in progress).
For this I hope you use kmin=1 and kmax=2^n-1

But also note that in this case the second smallest number 2^(n+1)-k>2^n>10^5, but the smallest number is 2^n-k<10^5 if and only if 2^n-1>k>2^n-10^5 ( because here 2^n-1>k ). It is important because my sieve will delete this prime from the list, because it has got a small prime factor (<10^5). It means that my program miss all octoproth in [2^n-10^5,2^n-2] range and you have to check it by another program ( it isn't very hard because it means you have to check at most 8*10^5 numbers for prp testing ).

And yes it is very important that after you have gotten your text file then check by another program the results, that these are really prime numbers. I think for n>50 it isn't very impossible to get a composite 3-prp numbers.

On page2 there were some results up to n=43 or something like that, have you checked these results, by my octo program? It would be very good.

It isn't impossible to write a faster program for these small n values, because prp testing is also very fast for these small n values.

Last fiddled with by R. Gerbicz on 2006-01-13 at 14:14
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