Primality testing 28237^31818-31818^28237 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 7
Running N+1 test using discriminant 13, base 8+sqrt(13)
Calling N-1 BLS with factored part 0.00% and helper 0.00% (0.01% proof)
28237^31818-31818^28237 is Fermat and Lucas PRP! (702.3976s+0.0034s)

Sieved with xyyxsieve

To be completed...