New files in the 270-280k range sieved to 2150bn are now available.

BTW, here is the number of candidates per k in the 270-280k range sorted in their decresing order together with the number of primes found so far.

Code:

k #cand #primes
870667875 1461 4
1952775825 1455 3
804003525 1415 3
460735275 1408 3
3467560635 1403 0
918332415 1367 4
697942245 1310 2
2022381375 1303 5
1738812075 1291 1
1626176475 1285 2
779602395 1283 0
1694614845 1278 3
663301485 1271 1
3276742755 1250 3
1325978745 1241 3
67342275 1211 1

Overall in the 200-400 range the order is slightly different but the first and the last

*k* are the same.

Observations:

1) k=3467560635 has a lot of candidates surviving sieving yet it is together with k=779602395 without primes.

2) k=2022381375 is in the middle by number of candidates but it produced the largest number of primes (5).

3) k=870667875 on the top produced many primes as expected (4).

4) k=3276742755 and k=1325978745 are near the bottom but with 3 primes each they are the most prolific.