20110829, 15:33  #56  
"Mark"
Apr 2003
Between here and the
3×17×131 Posts 
Quote:
How much memory does your program use? 

20110829, 16:12  #57 
Jun 2003
2·2,693 Posts 

20110829, 16:33  #58 
"Mark"
Apr 2003
Between here and the
1A19_{16} Posts 

20110829, 16:45  #59  
"Robert Gerbicz"
Oct 2005
Hungary
1573_{10} Posts 
Quote:
My code finds (p1)! mod p*p in polynomial time, this is achieved with that we determine for lots of primes at once (p1)! mod p*p. But for p~10^10 we don't have enough memory, there is a slowdown for (very) large primes. It doesn't really matter how much memory you have got, but with more memory it runs faster. I have choosen a parameter that it will use approx 1GB RAM for p~10^10. Determining for 10 million primes in a single search (p1)! mod p*p. Last fiddled with by R. Gerbicz on 20110829 at 16:52 

20110829, 18:05  #60  
"Mark"
Apr 2003
Between here and the
3·17·131 Posts 
Quote:
Either your algorithm is vastly different from mine (although it sounds similar) or you have written better optimized code. 

20110829, 18:05  #61 
Tribal Bullet
Oct 2004
5·709 Posts 

20110830, 12:09  #62 
"Robert Gerbicz"
Oct 2005
Hungary
11^{2}×13 Posts 
Mark, you missed p=3542985241 as a nearWilson prime: (p1)!==174p mod p^2. Now I am at 6 billions.

20110830, 12:30  #63 
"Mark"
Apr 2003
Between here and the
3·17·131 Posts 
I'll have to take a look. Either it is a code bug or the person who ran that range made a mistake. There were a number of ranges above 3e9 that I did not run and that was in one of them.

20110901, 16:13  #64 
"Robert Gerbicz"
Oct 2005
Hungary
11^{2}×13 Posts 
As I promised here you can download and use my code: https://sites.google.com/site/robertgerbicz/wilson
I've finished the search up to 1e10. There were two new nearWilson prime. 
20110901, 17:05  #65  
"Mark"
Apr 2003
Between here and the
15031_{8} Posts 
Quote:


20110901, 18:23  #66 
"Mark"
Apr 2003
Between here and the
1101000011001_{2} Posts 
I d/l'd your code, but haven't looked at it in detail. I did see that you use GMP, so your speed is rather surprising considering GMP overhead.

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