PFGW:
Primality testing 10^100000+4293973 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N+1 test using discriminant 5, base 5+sqrt(5)
Calling N-1 BLS with factored part 0.01% and helper 0.01% (0.03% proof)
10^100000+4293973 is Fermat and Lucas PRP! (3735.9813s+0.0400s)

To be completed...