Riesel 275 became a single-k base.

16*275^54825-1 is prime!

k=4 remains at n=100K, extending search to n=150K.

Results up to n=100K are attached.

Reserving R277 to n=25K.

R277 at 10.7K, 47 k remain, continuing to 25K.

S390 is proven

S308 is complete to n=25K; 1 prime found for n=5K-25K; 5 k's remaining; base released.
S311 is complete to n=25K; 1 prime found for n=5K-25K; only k=10 & 76 remaining; base released.
S318 is complete to n=25K; 2 primes found for n=5K-25K; only k=56 & 89 remaining; base released.
S410 is complete to n=25K; 1 prime found for n=5K-25K; 6 k's remaining; base released.

Reserving S326, S340, S386, and S414 to n=25K.

R470 is complete to n=100K; 1 k remaining; base released.

Max is reserving the 3 k's on S257 to n=100K. I talked him into that one since I'm trying to find primes for k=4 on some bases.

S386 is complete to n=25K; only k=30 remaining; highest prime 31*386^1010+1; base released.

S414 is complete to n=25K; only k=24 remaining; highest prime 61*414^236+1; base released.

Sierp 458
 

Sierp 458, the last k, tested n=25K-100K. Nothing found.

Results emailed. Base released

S326 is complete to n=25K; 2 primes found for n=5K-25K; 3 k's remaining; base released.

S340 is complete to n=25K; no primes found for n=5K-25K; 2 k's remaining; base released.

I've done some small-conjecture testing on some bases that had 1 or 2 k's remaining at n=5K the last 2-3 days. Here is what was done for bases <= 500:

S406 with CK=186 has only k=100 remaining; highest prime 16*406^420+1
S496 with CK=141 has only k=15 remaining; highest prime 27*496^551+1

Both have been tested to n=25K and are released.