1261*2^1753021-1 (527716 digits)

4001*2^2093286-1 (630146 digits)

This is only the second known prime for this k. The other is for n=18.

169*2^1590665-1 (478841 digits)

amphoria, nice prime!

1391*2^1754922-1 (528288 digits)

175*2^1711779-1 is prime! (515300 decimal digits) Time : 2823.373 sec.
(Second Megabit Drive)

125·2[SUP]2037752[/SUP]-1 ([URL="http://primes.utm.edu/primes/page.php?id=118123"]613427 digits[/URL])
105·2[SUP]2280078[/SUP]-1 ([URL="http://primes.utm.edu/primes/page.php?id=118128"]686374 digits[/URL])

4117*2^1807085-1 (543991 digits)

275·2[SUP]1846390[/SUP]-1 (555822 digits)
295·2[SUP]1832129[/SUP]-1 (551529 digits)
235·2[SUP]1824515[/SUP]-1 (549237 digits)
(Third Megabit Drive)

4015*2^1875453-1 (564572 digits)

1037*2^1760216-1 (529881 digits)

1253*2^1760738-1 (530039 digits)