20070213, 02:26  #133 
Dec 2006
Anchorage, Alaska
2·3·13 Posts 
This is only done for the remote chance that somebody who looks around and tries to report visibal primes before the actual finder does. As for doublechecking a found prime, I believe it is there to make sure the prime isn't a twin. If a computer somehow errors the second half of the test, and it is a twin, who else is going to look? So that's why it is doublechecked. The unit will be sent out again by the server if a prime is found to make sure it isn't a twin. If it was already sent out twice for normal doublechecking, then we just have to wait for both results. first one to send it wins. lol

20070531, 03:03  #134 
Jan 2005
Caught in a sieve
395_{10} Posts 
Somewhere, either here or on the PrimeGrid board, I saw someone in authority say that if a doublechecked number turns out prime, *both* people will get credit for the prime.

20070531, 05:42  #135 
Dec 2006
Anchorage, Alaska
2×3×13 Posts 
Only in PrimeGrid credits do both persons get credit for the prime. In other words, if you do a doublecheck of a prime, you will get 2.50 credits for it. However, you do not get to report the prime to the prime pages. also, you do not get the credit for finding the twin prime, should you be the one to doublecheck it. So don't confuse BOINC credits with prime reporting credits (2 seperate things here).
PrimeGrid will also add 1 prime found for your doublechecks on this page: http://www.primegrid.com/orig/top_prime.php 
20070531, 15:03  #136 
Jan 2005
Caught in a sieve
5·79 Posts 
Last fiddled with by Ken_g6 on 20070531 at 15:07 
20070601, 04:57  #137 
Dec 2006
Anchorage, Alaska
2·3·13 Posts 
Yup, just like I said. Only the originator of the prime gets to report it to the Prime Pages. Whayt he was complaining about was that the originator did not get an email (to report to the prime pages) for finding the prime.

20070603, 01:01  #138 
Jun 2007
2_{16} Posts 
i found a prime.
7682205561*2^3333331 
20070603, 01:02  #139 
Jun 2007
2_{16} Posts 
i found a prime.
7682205561*2^3333331 
20070604, 19:19  #140 
Apprentice Crank
Mar 2006
2·227 Posts 
qaz79,
I'll add the n=333,333 primes to the first post of this thread once they are too small for the top 5000 list. Until then, a complete list of primes found by TPS/PG can be found by clicking on "All of this project's primes" here (in case you didn't know): http://primes.utm.edu/bios/page.php?id=949 or http://primes.utm.edu/bios/page.php?id=950 
20080824, 13:24  #141 
Mar 2004
3·127 Posts 
Range completed:
99900M100000M biwema complete (7 primes) 99904218951*2^333333+1 99946436259*2^333333+1 99949817769*2^333333+1 99956002155*2^333333+1 99965117931*2^333333+1 99974141871*2^333333+1 99981453765*2^333333+1 no twins or (x)GFN... How far did Primegrid already search? How many primes did they find in that range? If PG completed about half of the range, it would still make sense to sieve a bit, even if the influence is not that high (besides the effort of removing the sieved candidates ftom the worktodo lists). If the range is double checked, even deeper sieve makes sense. Although it is inefficient to doublecheck twinprimesearch. Rather search a new range instead. There is enough available. (Or check +1 to find more primes and not to miss a twin). Although some double doublecheck (10%) could be useful to prevent cheating (getting credit with fake results) Last fiddled with by biwema on 20080824 at 13:27 Reason: forgot the +1 in the prime list 
20081011, 23:28  #142 
Apprentice Crank
Mar 2006
2·227 Posts 
Found a prime in my range, but it wasn't a twin:
99897184539*2^3333331 is prime! Time : 265.494 sec. 99897184539*2^333333+1 is not prime. Proth RES64: 5B14B97C16198C92 Time: 266.068 sec. 
20081102, 09:35  #143 
Jan 2007
DEUTSCHLAND !
3×7×13 Posts 
Hello, I have used the same methode like my triplet search.
After 12h, I found the first :) 73156402461*2^3333331 is prime , +1 not Interval : 73.15G  73.16G , k's left 2068. Searching is abort. With this methode it is possible to find 5 primes in a week , so I believe it. 
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