S290, CK=98, Four ks remaining.
Primes attached.
Base tested to 25k and released.

Sierpinksi Base 350
 

Conjectured k = 14. Reserving.

Completed the following to n=25K

R320 ck=106 primes=89 remain=3
R326 ck=110 primes=76 remain=2

Sierpinksi Base 350
 

Primes found:

[code]
2*350^1+1
3*350^1+1
4*350^2+1
5*350^20391+1
6*350^2+1
7*350^84+1
8*350^1+1
9*350^3+1
10*350^1294+1
11*350^1+1
12*350^1+1
13*350^6+1
[/code]

k=1 is a GFN. With a conjectured k of 14, this conjecture is proven (unless a GFN prime is required).

[QUOTE]k=1 is a GFN. With a conjectured k of 14, this conjecture is proven (unless a GFN prime is required). [/QUOTE]

We never require k=1 to be tested on any base. BTW 1*350^2+1 is prime.

Sierpinski bases 458 and 497
 

Reserving.

Here are the final 2 of 9 bases from my recent k=2 effort as shown in the bases 501-1024 thread. The following bases have been searched to n=25K and are released:

R380; CK=128; k=38, 50, 63, & 79 remain; highest prime 125*380^6358-1
S416; CK=140; k=73 & 118 remain; highest prime 31*416^23572+1

Collective primes for n=5K-25K:
125*380^6358-1
13*416^18232+1
31*416^23572+1

As points of interest:

The only base <= 500 that still has k=2 remaining at n=10K but is not shown on the pages is R303. But with a conjecture of 85368, that will be a toughie to search the entire base.

Here is a complete list of bases <= 500 that have k=2 remaining (and their search depths):
R170 (100K)
R303 (10K by me; not shown on pages)
S101 (100K)
S218 (100K)
S236 (25K)
S365 (25K)
S383 (25K)
S461 (75.7K)
S467 (25K)

The Sierp side has a lot of difficulty with k=2, 4, & 8 relative to the Riesel side.


Gary

Sierpinski Bases 483, 332, 480, and 429
 

Reserving

Sierpinski results
 

Base 458:

[code]
2*458^105+1
3*458^107+1
4*458^66+1
5*458^7+1
6*458^1+1
7*458^6+1
8*458^11+1
9*458^2+1
10*458^5952+1
11*458^1+1
12*458^13+1
14*458^79+1
15*458^1+1
[/code]

k=13 remains at n=25000. Releasing.

Base 497

[code]
2*497^1339+1
4*497^1898+1
6*497^169+1
10*497^4+1
12*497^4+1
14*497^1+1
[/code]

k=8 remains at n=25000. Releasing.

R341 is proven
CK=20

Largest prime

8*341^4966-1

Attached are the results

Reserving R272 (1 k) and R275 (2 k's) to n=100K.