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

[robert44444uk]

Kosmaj

Just what a huge prime and so close to being aesthetically pleasing! Huge congrats.

I have taken 15 to 620K now, with no further primes.

Regards

Robert Smith

[Templus]

I am releasing k=65, it's done until n=310k. I have sieved until 158G.
If anyone is interested in the sieve-file , just let me know!

[Templus]

Well...I'm reserving k=65 again!!
It's quite a heavy one though!

[Templus]

k=65 has been completed until n=365000, but no new primes found It has been sieved until 200G and there are about 30000 tests left

Continuing on this k!

[Kosmaj]

Templus
I suggest you sieve more, at least to 500G, or if you can to 1T. Especially if you plan to continue to n=500k. If you test on two machines, stop LLR on one and run NewPGen for a week.

BTW, many k's produced one or more primes in the n=350-400k range and I hope k=65 will follow the pattern!

Good luck.

[Templus]

k=65 has been tested until n=380000, sieved until 400G (still sieving), and no new primes found. About 29000 k's to test until n=1M.

[Kosmaj]

k=55 checked to n=520k, no new primes, stopped and released.

k=165, primes for n=221667, 236051, 246426, and 325922
checked to n=350k, in progress.

And finally, after almost half a year, next prime for k=77:

77*2^855770-1 is prime (257615 digits)

k=77 checked to n=857k, in progress.

[Templus]

k=65 has been tested until n=395000, sieved until 500G and no primes found.

I am also reserving k=149 to test until ...? Let's hope I'll find a prime for this one! :-)

The top5000 says that this k has primes for n=212460, which isn't listed on the progress site

[Kosmaj]

Templus,
149*2^212460-1 was found by L70, Mr. Yamada, who doesn't report either to us or to Dr. Keller. [In February, together with two other persons he found a huge Proth prime 7*2^1491852+1 with almost 450,000 digits!] So we don't know what n's he checked. I don't think he went far beyond n=230k but he definitely has resources to go much further. I'll try to contact him and I ask him. I don't have his e-mail address but I know a person who does.

But k=149 has low weight and to n=212460 only 12 primes have been found. Of course the next prime can be very close but more likely it's in the 400-600k (?) range. If you want to find some primes faster I suggest k=93 or k=99, both checked only to 210k, with higher weights and many primes already found.

In any case, good luck!

[Templus]

Well...in that case I'll go check k=93

Thanks for your input! :)

[Templus]

Hi all,

k=65 has been checked until 418000, sieved until 550G (still sieving) and there are 27000 numbers left! Unfortunately, there are no new primes! I don't know what's wrong with this k, but when I find a prime, it will be quite a huge one! I saved all the RES64 numbers, so it can be double-checked later if needed.

k=93 has been checked until 250000, sieved until 70G. I am working on it.