mersenneforum.org Riesel Primes k*2^n-1, k<300 [Was "k=1"]
 Register FAQ Search Today's Posts Mark Forums Read

 2005-08-16, 15:32 #331 Templus     Jun 2004 2×53 Posts 93*2^251199-1 is prime! Finally a newly fresh prime for me! ^^ It has 75621 digits and is submitted under prover-code L128. (LLR,15k and my username)
 2005-09-08, 22:24 #332 Keller   May 2004 22·7 Posts Testing k=99
 2005-09-19, 21:42 #333 Chaos   Sep 2005 5 Posts Can I work on k=81? It seems to be available to the webpage I would also like to work on k=243, is that also available? Last fiddled with by Chaos on 2005-09-19 at 21:45
 2005-09-19, 23:00 #334 Kosmaj     Nov 2003 2·1,811 Posts k=81 is available from n=220k. k=243 although it looks available has been checked by p48 and he found 3 primes for n between 387k and 744k. The exact range he checked is not known because he reports neither to us nor to Keller. It's possible that the 230-350k range was not checked. Last fiddled with by Kosmaj on 2005-09-19 at 23:01
 2005-09-20, 03:02 #335 Chaos   Sep 2005 5 Posts Ill work only on k=81 then. Thank you.
 2005-09-20, 03:36 #336 Chaos   Sep 2005 5 Posts Can I take 127 instead of 243. This one seems to be free. Thank you Last fiddled with by Chaos on 2005-09-20 at 03:37
 2005-09-20, 05:06 #337 Kosmaj     Nov 2003 2×1,811 Posts k=127 is available from n=230k. But be careful, it has very low weight, there may not be many primes there. Still, not many candidates will survive sieving so you can reach 300k or 400k quickly, and with some luck find a prime. In any case, please keep us informed about your progress (once in a month or so or when you reach certain milestones like n=300k, 500k, or 1M, depends how far do you intend to go), and definitely when you stop working on them. Thanks and good luck! Last fiddled with by Kosmaj on 2005-09-20 at 05:12
2005-09-29, 07:28   #338
Thomas11

Feb 2003

190710 Posts

Quote:
29*2^1478344-1 is prime!

 2005-10-04, 04:52 #339 Kosmaj     Nov 2003 2·1,811 Posts Thomas, congrats on a huge prime! Can you tell us about the limits you reached for k's you work on now, IIRC you were also testing k=11? It's a pity almost nobody reports here anymore. Masser and JCS (Sax) disappeared, although Masser reported some of his limits to Wilfrid Keller. Now, my recently reached limits are given below, no new primes. k=7, to n=1.3M (in progress to 2M) k=59, in the 500-620k range (in progress to 1M) k=87, to n=580k (in progress to 1M) k=95, to n=440k (in progress to 700k) k=165, to n=590k (will stop at 600k) Also, by joint effort, k=65 was processed to n=600k. I'd like to suggest that we create a new project k*2^n-1, k<300 (or k<250 since PrimeSearch works on some k's in the 250-300 interval) where we can report primes found with help of coordination provided by this thread since the "15k Search" is not the right project to report all such primes. Any suggestions for the project name? "k*2^n-1, k<300" is an obvious but a bit clumsy candidate, while "Riesel Primes" can be confused with "Riesel Sieve". Last fiddled with by Kosmaj on 2005-10-04 at 04:56
 2005-10-04, 22:38 #340 Kosmaj     Nov 2003 2·1,811 Posts Karsten Bonath If you read this please note that 97*2^n-1 is already checked to 800k. Please stop your tests from 250k and either select another k, or proceed from 800k. Thanks! BTW, I'm now trying to update the Riesel List originally compiled by Joss. Please, kindly report your achieved limits for respective k's on the list. A partially updated list will be available in about half an hour. Last fiddled with by Kosmaj on 2005-10-04 at 22:39
 2005-10-05, 08:57 #341 Thomas11     Feb 2003 1,907 Posts Kosmaj k=11 is tested to n=1080000. k=29 is tested to n=1480000. There is also a megabit-prime for k=11, which was found earlier: 11*2^1044086-1 (already on Wilfried Keller's list)

 Similar Threads Thread Thread Starter Forum Replies Last Post CRGreathouse Number Theory Discussion Group 51 2018-12-16 21:55 URoy Miscellaneous Math 15 2016-11-17 22:52 Batalov And now for something completely different 12 2014-11-16 19:03 Kosmaj Riesel Prime Search 21 2012-09-14 09:51 nitai1999 Software 7 2004-08-26 18:12

All times are UTC. The time now is 07:12.

Sat Jan 23 07:12:37 UTC 2021 up 51 days, 3:23, 0 users, load averages: 2.25, 2.62, 2.62