While searching for large GFNs, I found a [URL="http://primes.utm.edu/primes/page.php?id=98633"]4*257^160422+1[/URL] prime.

I didn't realize that S257 didn't have known primes for k=4, so this is useful for CRUS, and S257 is now a 1-ker with k=40.

Wait, no, I only tested k=4 and only in context of other 4*b^n+1 candidates (only b's with n=4m+2 remaining after small low sieve).

k=40 is at 100K for S257, as far as I understand.

[QUOTE]I didn't realize that S257 didn't have known primes for k=4, so this is useful for CRUS, and S257 is now a 1-ker with k=40. [/QUOTE]

Yes, it is useful.

Serge, did you test k=40 to n=160K also. If so, can you post the results?

No, I simply tested k=4, b=257 from n>=1 (and still going).

(I've already checked b=17, b=83 and some others in the past -- all of these had small primes, so their existing search limits were low. I had repeated the same search strategy here.)

[QUOTE=Batalov;253227]Wait, no, I only tested k=4 and only in context of other 4*b^n+1 candidates (only b's with n=4m+2 remaining after small low sieve).

k=40 is at 100K for S257, as far as I understand.[/QUOTE]

Serge,

Can you add CRUS to the prover code for this prime?


Thanks,
Gary

Well, I did this for my own GFN search ([URL="http://primes.utm.edu/bios/code.php?code=p286"]code p286[/URL]), but I've emailed C.Caldwell to change code to [URL="http://primes.utm.edu/bios/code.php?code=p258"]code p258[/URL].

EDIT: I agree with your message below. Most of the bases I am testing are not needed for CRUS, but some are and I don't see any reason to not to add CRUS.

[QUOTE=Batalov;253239]Well, I did this for my own GFN search ([URL="http://primes.utm.edu/bios/code.php?code=p286"]code p286[/URL]), but yeah, ok, I'll email C.Caldwell to change code to [URL="http://primes.utm.edu/bios/code.php?code=p258"]code p258[/URL].[/QUOTE]

Ah, OK. I saw that you were doing it for a GFN search but I thought you were doing that as a result of this project. That's a gray area. It's up to you how it is reported. Regardless; nice find! :smile:

Reserving R366 to n=25K

Dmitry reported in a PM that S333 is complete to n=25K. 73 k's were found prime for n=2.5K-25K. 51 k's remain. The base is released.

Reserving S396 to n=25K.

Here is the status of S396 at 10K - for the webpages.
31 [I]k[/I]'s remain. [SIZE=1](technically, 32. One [I]k[/I] is eliminated in a higher speed-test run for a few low bases)[/SIZE]
[SIZE=1][/SIZE]
Not bad for an even base (and not 1(mod 3)) with CK of 5253.
Continuing to 25K.