Primality testing 26749^27768-27768^26749 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Running N+1 test using discriminant 11, base 1+sqrt(11)
Calling N-1 BLS with factored part 0.01% and helper 0.00% (0.02% proof)
26749^27768-27768^26749 is Fermat and Lucas PRP! (513.4033s+0.0020s)

Sieved with xyyxsieve

To be completed...