1693514745*2^370471-1 (111533 digits)

Finally got a big one!

[B]253*2^1722623-1[/B] (518564 digits)

Currently ranked 44th largest.

:bounce wave:

Wow! Congrats!

Really WOW! :smile: Congratulation!!!!

Guacamole.

That's ample reward for testing these semi-low-weight k<300 values. Nice find.
-Curtis

Congrats Kosmaj!

Congrats
 

:shock: :shock: :shock: :shock:
HUGE prime and HUGE congrats Kosmaj!
How many computers are you using?

nuggetprime

Thank you all! I was surprised myself. :smile: I began working on k=253 about half a year ago because it was the only k<300 with no gigantic primes (with more than 10,000 digits). I began at 1165k where Joss stopped. The majority of tests was done on a single 3GHz P-4. Currently one test requires almost exactly 100 minutes (5970sec for the prime) and I was about to stop at 1.75M. I have sieved values to n=3M through p=5T. The average "density" is 3.63 values per 1000 n.

Congrats! I hope you also find a prime for k=7, as that k is long overdue for a prime.

52654604145*2^314483-1 (94680 digits)

52654604145*2^315664-1 (95036 digits)