Primality testing 31688^36783-36783^31688 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 7
Running N+1 test using discriminant 13, base 1+sqrt(13)
Calling N-1 BLS with factored part 0.01% and helper 0.01% (0.03% proof)
31688^36783-36783^31688 is Fermat and Lucas PRP! (1418.3781s+0.0028s)

Sieved with xyyxsieve

To be completed...