Primality testing 2768^19597-19597^2768 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N+1 test using discriminant 7, base 8+sqrt(7)
Calling N+1 BLS with factored part 0.01% and helper 0.00% (0.04% proof)
2768^19597-19597^2768 is Fermat and Lucas PRP! (194.5277s+0.0018s)

Sieved with xyyxsieve

To be completed...