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2020-09-08, 20:02   #375
bur

Aug 2020

2×3×5 Posts

Quote:
 Originally Posted by VBCurtis Nope. But the opposite isn't true, either.
But then I would say low weight doesn't really matter. Either I test 100000 candidates for a given k and find 10 primes or I test 10000 and find one. Then move to the next low weight k and in the end I end up with the same number of LLRs and primes. Just spread over more than one k. Is it like that?

 2020-09-08, 23:30 #376 VBCurtis     "Curtis" Feb 2005 Riverside, CA 2·11·199 Posts We have no evidence otherwise, though some folks around here do think otherwise. I test a couple low-weight k's as well as some of the highest; I like finding anomalies, but I don't think my choices are more prime-worthy per unit of search effort.
 2020-09-09, 07:21 #377 bur   Aug 2020 368 Posts I looked into the matter why only primes show up as n for low n values. Here are some restrictions I found: If $n \equiv 0 \textrm{ mod } 2$ the Riesel number will be divisible by 3 (n = 2, 4, 6, 8, 10, ...) If $n \equiv 1 \textrm{ mod } 10$ the Riesel number will be divisible by 11 (n = 11, 21, 31, 41, 51, ...) If $n \equiv 1 \textrm{ mod } 8$ the Riesel number will be divisible by 17 (n = 9, 17, 25, 33, 41, 49, ...) If $n \equiv 15 \textrm{ mod } 20$ the Riesel number will be divisible by 41 (n = 15, 35, 55, 75, ...) If $n \equiv 19 \textrm{ mod } 70$ the Riesel number will be divisible by 71 (n = 19, 89, 159, 229, ...) There might be more. I am not sure though if this will rather hit composites than primes. The 2nd condition removes 11, 31, 41, 71, so it doesn't really seem like it. Last fiddled with by bur on 2020-09-09 at 07:35
 2020-09-09, 09:54 #378 bur   Aug 2020 1E16 Posts Haha, I just realized this is probably trivial and occurs for every divisor... yes, I'm not that good at math. :)
 2020-09-09, 20:46 #379 bur   Aug 2020 2·3·5 Posts Here are the n values for Riesel primes with k = 1281979 and n <= 100000 3 7 43 79 107 157 269 307 373 397 1005 1013 1765 1987 2269 6623 7083 7365 10199 16219 26143 32557 38165 47167 47863 70373 94723 95167
 2020-09-19, 13:26 #380 Happy5214     "Alexander" Nov 2008 The Alamo City 2·193 Posts The (near-)Woodall k's listed in https://www.mersenneforum.org/showpo...&postcount=363, again except for k=1993191, have been completed to n=375k. The only prime found was 667071*2^373497-1. Edit: Another prime, 667071*2^358286-1, was already reported (by me) to the Prime-Wiki in August, so I accidentally left it off here. Last fiddled with by Happy5214 on 2020-09-19 at 13:38 Reason: Forgot a prime
2020-10-01, 11:16   #381
Happy5214

"Alexander"
Nov 2008
The Alamo City

38610 Posts

I've completed the remaining RPS 9th and 10th Drive k's with missing ranges from n=300k to 325k. 18 primes were found, which are attached. It'll probably be until the end of 2021 before they're finished to n=400k, the ultimate goal.
Attached Files
 RPS_300-325K.txt (255 Bytes, 7 views)

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