Riesel Primes k*2^n-1, k<300 [Was "k=1"]

[Kosmaj]

Thomas,

CONGRATS! The k=3 huge prime yesterday and the k=11 one today, you cannot deny that these two days have been very lucky for you.

Happy hunting!

(btw, where are those smilies, cannot find them...)

[robert44444uk]

For the group's information, 15 is now at 505000 with no further primes. Sadly I have this running on a very slow machine.

Regards

Robert Smith

[Thomas11]

11*2^743322-1 is prime!

[Kosmaj]

k=7, checked to n=1012000, in progress
k=13, to 1000000 (1M), stopped
k=21, to 760000, in progress
k=35, 35*2^252910-1 is prime, checked to 360000, in progress
k=53, to 520000, stopped
k=77, 77*2^387680-1 is prime, checked to 388000, in progress

Happy hunting to all!

[Kosmaj]

77*2^441528-1 is prime!

k=77 checked to 450000, continuing.

[Kosmaj]

I'd like to congratulate Jeffrey (L38) on many primes he found recently, including the just reported 47*2^450470-1 but I think it will be nice if he can post here the ranges he processed and the ranges he is working on now so that the others can better decide which k to check next. I see that he is actually informing Joss directly (as I don't remember he ever posted in this thread) but with a large delay. I wanted to mail him and tell him this directly but he has no e-mail address listed on his Top-5000 biography page. Posting above info will be greatly appreciated and will help the progress of the project.

We have others not reporting either, like g267 (Grobstich) on k=17, 63, 65 and possibly other k's and L33 (Chaglassian) on k=73, 103 etc. but there is little we can do about that.

[Kosmaj]

I'm now working on k=55 and after some quick tests I found that
55*2^218043-1 is prime.

Current status:
k=55, to 220k, in progress
k=21, to 820k, in progress
k=35, to 420k, stopped
k=77, to 480k, in progress

Happy crunching!

[Harvey563]

Here's my recent activity:

243*2^206302-1 is prime!

241*2^n-1 200000 to 230000 11/3/4 [none] completed
243*2^n-1 200000 to 219000 11/5/4 [206302] continuing to 230000
245*2^n-1 200000 to 230000 11/2/4 [none] completed
247*2^n-1 200000 to 230000 11/1/4 [none] completed
249*2^n-1 200000 to 230000 11/1/4 [none] completed

Harvey563

[JCS]

Originally Posted by Kosmaj

I'd like to congratulate Jeffrey (L38) on many primes he found recently, including the just reported 47*2^450470-1 but I think it will be nice if he can post here the ranges he processed and the ranges he is working on now so that the others can better decide which k to check next.

Thanks! Ok, here goes. My upper limit is n=500k, except for k=9.

k=9: at 744k
k=33: at 410k
k=43: complete to 500k
k=51: at 475k (51*2^468417-1 is prime!)
k=59: at 360k (59*2^358276-1 is prime!)
k=69: complete to 500k
k=105: at 430k
k=117: at 363k

Completed previously: 47 (500k), 101 (500k), 109 (350k), 119 (500k), 289 (300k)

Jeffrey

[SlashDude]

Update on k=23

I have tested this one to n=1,000,000! I am still testing it to higher n's

[Kosmaj]

Status of k's reserved before:
k=7: [to n=1050000] in progress
k=21: [850000] continuing to 1M
k=55: prime for n=253047 [280000] continuing to 520k
k=77: [520000] in progress

The following 7 k's I've been testing in the 210-400k range.
k=57: 239854 [330000]
k=59: 358276 already reported by JCS [400000]
k=61: [280000]
k=67: [400000]
k=83: 216954 [260000]
k=85: [370000]
k=87: [310000]

I "collided" with JCS at k=59 but I was using a machine without permanent access and I couldn't stop it earlier.