On 2017-09-17 at 21:30 PrimeGrid user Ben Maloney returned the following result:
168451*2^19375200+1 is prime! (5832522 decimal digits). That prime eliminates k=168451 from the Prime Sierpinski Problem. The prime will show up on
http://www.primegrid.com/stats_psp_llr.php as soon as the Top 5000 Primes site verifies it.