Primality testing 27905^28578-28578^27905 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Running N+1 test using discriminant 13, base 6+sqrt(13)
Calling N-1 BLS with factored part 0.01% and helper 0.01% (0.03% proof)
27905^28578-28578^27905 is Fermat and Lucas PRP! (581.6011s+0.0021s)

Sieved with xyyxsieve

To be completed...