Primes found - Page 3

lsoule · 2006-06-13, 21:24

268964355*2^195000-1 is prime! Time : 90.980 sec.
269367765*2^195000-1 is prime! Time : 100.803 sec.

Citrix · 2006-06-14, 02:59

196134045*2^195000+1 is prime!

My first prime for this project.

Too bad it does not go into to Top 5000.

victor · 2006-06-14, 06:33

Do you mean 196134045*2^195000-1 is prime too???

Citrix · 2006-06-14, 07:49

No the -1 is not prime

victor · 2006-06-14, 13:55

Ok :)
And why do you check for +1 first?

pacionet · 2006-06-14, 14:45

What is the actual ratio PRIMES / MILLIONS TESTED ?

Citrix · 2006-06-14, 15:52

Quote:

Originally Posted by victor

Ok :)
And why do you check for +1 first?

Does it make any difference, which I check first.

victor · 2006-06-14, 16:07

Quote:

Originally Posted by Citrix

Does it make any difference, which I check first.

Not at all, in fact I don't care. It was only for information.

Citrix · 2006-06-14, 16:54

I have an LLRnet server set up for +1 numbers, so I prefer working on +1 numbers. If I wanted to do -1 search, I will have to modify all my computers, which will be a hassle. Hence, I tested +1 primes.

pacionet · 2006-06-15, 07:10

Ok I computed actual ratio: it should be 47 primes on 255 Millions tested, that is

0.184313

It means we are finding a prime every 5.42 Millions.

We are slightly under previsions (between 0.2 and 0.25) .

biwema · 2006-06-15, 09:43

Where The number of twins remains constant (After sieving to 83T, a range of 24.7G and 10005865 Candidates it is one twin every 13.77G), the average Gap between Primes is increasing proportiona to the ratio of the log(sieving limit).
That means sieving to 45 bit instead if 44 bit means a 45/44 larger gap between the primes. (Reason: The sieve is biased to finding twins)

The current value at 83T is a prime every 5.83M.

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2006-06-13, 21:24	#23
lsoule Nov 2004 California 2³×3×71 Posts	2689643552^195000-1 is prime! Time : 90.980 sec. 2693677652^195000-1 is prime! Time : 100.803 sec.

2006-06-14, 02:59	#24
Citrix Jun 2003 3×5×107 Posts	196134045*2^195000+1 is prime! My first prime for this project. Too bad it does not go into to Top 5000.

2006-06-14, 06:33	#25
victor Oct 2005 Fribourg, Switzerlan 11111100₂ Posts	Do you mean 196134045*2^195000-1 is prime too???

2006-06-14, 07:49	#26
Citrix Jun 2003 1605₁₀ Posts	No the -1 is not prime

2006-06-14, 13:55	#27
victor Oct 2005 Fribourg, Switzerlan 2²×3²×7 Posts	Ok :) And why do you check for +1 first?

2006-06-14, 14:45	#28
pacionet Oct 2005 Italy 3·113 Posts	What is the actual ratio PRIMES / MILLIONS TESTED ?

2006-06-14, 16:54	#31
Citrix Jun 2003 645₁₆ Posts	I have an LLRnet server set up for +1 numbers, so I prefer working on +1 numbers. If I wanted to do -1 search, I will have to modify all my computers, which will be a hassle. Hence, I tested +1 primes.

2006-06-15, 07:10	#32
pacionet Oct 2005 Italy 3·113 Posts	Ok I computed actual ratio: it should be 47 primes on 255 Millions tested, that is 0.184313 It means we are finding a prime every 5.42 Millions. We are slightly under previsions (between 0.2 and 0.25) .

2006-06-15, 09:43	#33
biwema Mar 2004 3·127 Posts	Where The number of twins remains constant (After sieving to 83T, a range of 24.7G and 10005865 Candidates it is one twin every 13.77G), the average Gap between Primes is increasing proportiona to the ratio of the log(sieving limit). That means sieving to 45 bit instead if 44 bit means a 45/44 larger gap between the primes. (Reason: The sieve is biased to finding twins) The current value at 83T is a prime every 5.83M.