PFGW Fermat Prp b=3,7 and BLS test :
PFGW Version 3.7.10.64BIT.20150809.x86_Dev [GWNUM 28.7]
Primality testing 2^608541-608541^2 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 11
Running N+1 test using discriminant 19, base 1+sqrt(19)
Calling N+1 BLS with factored part 0.01% and helper 0.00% (0.02% proof)

2^608541-608541^2 is Fermat and Lucas PRP! (2827.2111s+0.0002s)

To be completed...