20101126, 16:17  #23 
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17·251 Posts 
I just finished checking on the list of Proth primes for Riesel counterpart twins for the 20101124 list. No new primes found.

20101129, 16:44  #24 
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17×251 Posts 
16294579238595022365*2^7±1 are prime (22 digits)
I've finished checking the Riesel list of 20101126. This was the only new twin prime. 
20101129, 19:54  #25  
Mar 2006
Germany
2×3^{2}×157 Posts 
Quote:
I've nothing changed on the 10^10 Summary page since 20101018. 

20101129, 20:00  #26  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17×251 Posts 
Quote:


20101129, 20:05  #27  
Mar 2006
Germany
2·3^{2}·157 Posts 
Quote:
But thanks for the checking of the twin list. 

20110117, 16:10  #28  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17·251 Posts 
Quote:
The PRP testing is currently at n=475K. There are 275 candidates remaining. In the event (with a dismally low chance of under 3%) that one of those is prime, I'll have found a probable twin prime. AFAIK that would only be officially recognized as a nontwin PRP on the top PRPs list, as it would be too large to prove, but it would still be highly likely to be the largest pair of twin primes known. Last fiddled with by MiniGeek on 20110117 at 16:55 

20110117, 19:55  #29 
Just call me Henry
"David"
Sep 2007
Cambridge (GMT)
13·19·23 Posts 
What is the record for a non +1 twin prime? Is there a type non +1 that is easy to prove and sieve?

20110117, 21:50  #30  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
10253_{8} Posts 
Quote:
Status: PRPing: n=513365, 209 candidates remain, sieving more before continuing. proving PRPs: n=4414, 11 candidates remain. (over 1 hour per test; I'm not sure I'll go all the way with this, 2^15513 is starting to look pretty large...might take a few days just for that test) Last fiddled with by MiniGeek on 20110117 at 22:09 

20110118, 17:09  #31 
Just call me Henry
"David"
Sep 2007
Cambridge (GMT)
5681_{10} Posts 
If you give in before 5789*2^15513+1, +3 then I would do it. This one is worth testing because it is the largest we know of in its class.

20110118, 18:18  #32  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
10253_{8} Posts 
Quote:
For clarity, here are the largest PRPs I found and who has them reserved for proving: Code:
517*2^6098+3 and below MiniGeek (done, certificates in DB) 7315*2^64233 MiniGeek (done, certificate in DB) 1381*2^6512+3 MiniGeek (done, certificate in DB) 7027*2^130173 [unreserved] 755*2^134743 [unreserved] 5789*2^15513+3 henryzz Also, a status on my PRPing: I have split it into 3 parts and am running it on Prime95, (multiple cores and automatic P1 makes it much better than PFGW when the numbers are this size ) the lowest is at n=819630, and there are 29 candidates left to PRP. The largest one alone will probably take a couple days, since it is so large: 2^134669173. If that turns out PRP, that would be incredible! Besides being the largest PRP, with 4053946 digits, it would (probably) be a twin with a Mersenne prime. Unfortunately that is extremely unlikely... Last fiddled with by gd_barnes on 20110121 at 09:05 Reason: update completion status 

20110120, 11:53  #33 
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
10AB_{16} Posts 
Code:
1381*2^6512+3 and below MiniGeek (done, certificates in DB) 7027*2^130173 [unreserved] 755*2^134743 [unreserved] 5789*2^15513+3 henryzz 2^134669173 would have taken a little over two days, but I put it on two cores for most of it, so it took closer to one day. Because it wasn't sieved very well, (only to 5 billion, or about 2^32) Prime95 chose P1 bounds that gave it a 20% chance of finding a factor. Unfortunately it did not find a factor, even with such generous bounds, so I had to test it. Alas, the largest known twin Mersenne prime (i.e. 2^p1 and (2^p3 or 2^p+1) are prime) is just p=5: 29 and 31. Just for fun, here are all known primes that are twin Mersenne or Fermat primes: Code:
2^16+1, +3 (65537, 65539) 2^4+1, +3 (17, 19) 2^51, 3 (29, 31) 3, 5, and 7, by various formulas (3=2^1+1=2^21, 5=2^1+3=2^2+1=2^33, 7=2^2+3=2^31) Last fiddled with by MiniGeek on 20110120 at 12:22 
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