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 2016-04-16, 02:08 #2 wombatman I moo ablest echo power!     May 2013 1,741 Posts Definitely interested in helping, but can't at the moment. I'll keep watching this space for updates so I can jump in later. Screw it, I'll work on base 26 up to n=100,000 Last fiddled with by wombatman on 2016-04-16 at 02:12
2016-04-16, 03:44   #3
rogue

"Mark"
Apr 2003
Between here and the

10111100101002 Posts

Quote:
 Originally Posted by wombatman Definitely interested in helping, but can't at the moment. I'll keep watching this space for updates so I can jump in later. Screw it, I'll work on base 26 up to n=100,000
Thanks for joining.

Would you mind starting from n=1? I doubt it would take long to catch up to the range that was searched.

 2016-04-16, 06:23 #4 axn     Jun 2003 2×5×479 Posts Is there any mathematical reason why smaller bases (12, 18, 20, 24, etc..) have not been searched?
2016-04-16, 14:19   #5
rogue

"Mark"
Apr 2003
Between here and the

22×3×503 Posts

Quote:
 Originally Posted by axn Is there any mathematical reason why smaller bases (12, 18, 20, 24, etc..) have not been searched?
None that I know of. You can search any even base. I would expect even base 4 to have some primes.

2016-04-16, 14:56   #6
axn

Jun 2003

479010 Posts

Quote:
 Originally Posted by rogue None that I know of. You can search any even base. I would expect even base 4 to have some primes.
Base 4 is covered by base 2 (since 4^n = 2^(2n)). Similarly, any perfect power will be covered by its base. So, 4,8,16,32,36,etc... need not be searched.

EDIT:- I'll work on base-12 to 50,000. I'll sieve base-18 to 100,000 but not sure how far I'm willing to test. Will know further once I'm done with base-12.

Last fiddled with by axn on 2016-04-16 at 15:02

2016-04-16, 15:30   #7
rogue

"Mark"
Apr 2003
Between here and the

22·3·503 Posts

Quote:
 Originally Posted by axn Base 4 is covered by base 2 (since 4^n = 2^(2n)). Similarly, any perfect power will be covered by its base. So, 4,8,16,32,36,etc... need not be searched.
Duh!

 2016-04-16, 18:04 #8 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 918210 Posts I'll run bases 10 and 20 to 100k, and 30 and 40 to 70k for starters.
2016-04-16, 20:35   #9
wombatman
I moo ablest echo power!

May 2013

33158 Posts

Quote:
 Originally Posted by rogue Thanks for joining. Would you mind starting from n=1? I doubt it would take long to catch up to the range that was searched.
I'll let the current search (running to P=1e12) finish and then I'll run the range from n=1 up to where I started already.

 2016-04-16, 22:55 #10 rogue     "Mark" Apr 2003 Between here and the 22×3×503 Posts Make sure you sieve deeply enough. For base 2, I'm continuing to sieve up to 1e13 and it is still removing factors at more than one an hour. Granted higher bases won't need to be sieved as deeply to find prime with the same number of bits for lower bases, but I wouldn't be surprised if most bases need to be sieved to at least 1e12.
 2016-04-17, 15:10 #11 lalera     Jul 2003 22·151 Posts hi, I do like to reserve base=74 n=1 to 100000

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