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

[Templus]

Kosmaj,

I'm still working on k=93, it has been tested until n=290000.

[masser]

Originally Posted by Kosmaj

It's a pity almost nobody reports here anymore. Masser and JCS (Sax) disappeared, although Masser reported some of his limits to Wilfrid Keller.

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".

I stopped reporting here because the website was rarely updated. I did report my ranges and results to Wilfred Keller's website. I tested k=111, 123, 153, 159, 171, 183, 189, 219 and 225 up to n=700,000. I sieved these k-values up to n=1,000,000, but I believe I won't be able to finish them on my own. If anyone is interested, I'd be willing to upload the files to the forum (if given proper permissions) and people could work on them, as with 210885, etc.

As for a name for the independent project, may I suggest "Small k Riesels"?

regards,
masser

[Kosmaj]

Thanks for your reports!
I included your data into the stats file. I also included recent reservations made by Chaos. Next, I'll try to sort out intervals tested by Jeffrey. I'll try to conatct him but I'm not sure is that going to work.

As for the new project, I'll make a concrete proposal when I have a new reportable prime. I hope you guys will join the project later. We can also move some of our already found primes to respecive new project's prover's codes. Thanks.

[Kosmaj]

Below is your post of January 16, 2005. Are you still working on these two k's? Please tell us about your progress. Thanks.

Originally Posted by Keller

Reserving k=237 from 210k to 500k
and k=241 from 230k to 500k

[Thomas11]

I've just found another megabit prime: 11*2^1104606-1

[Kosmaj]

Congrats on yet another big prime!

I just uploaded the latest stats table with updated reservations and recently found primes including this one.

[Cruelty]

I'll give "25" a shot

[NiceMedTexMD]

I guess i'm more confused than most.. but with this thread, what primes are being looked for, and how would I help out?

Dr. Mike..

[Kosmaj]

Mike,
Here we are searching for primes of form k*2^n-1, where k<300. You can select k values from this table. For sieving instructions please check here.

Now, I'm reserving:
k=63, from n=200 to n=500k, and
k=97, from n=800k forward.

k=63 has a prime for n=218694 but processed intervals of n were never reported.

k=97 is the only k<300 with no primes for n>10k

[Templus]

I'm currently sieving k=93 in the range n=300000-400000, currently at 225 bn and 4830 tests left.
The k has been tested until 309k and I am going to finish it until 400000. One is free to take this k from n=400000 upwards now, ask me for a sieve file.

[lsoule]

I'd like to reserve k=69 from n=500k onwards.

thanks,
Larry