Primality testing 26726^30173-30173^26726 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N-1 test using base 5
Running N-1 test using base 13
Running N+1 test using discriminant 19, base 1+sqrt(19)
Calling N+1 BLS with factored part 0.01% and helper 0.00% (0.03% proof)
26726^30173-30173^26726 is Fermat and Lucas PRP! (967.4631s+0.0023s)

Sieved with xyyxsieve

To be completed...