1st PRP for 2^n-174673.

Sieved to P=200G.

Primality testing 2^54761-174673 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 239
Running N+1 test using discriminant 3, base 1+sqrt(3)
Calling N+1 BLS with factored part 0.05% and helper 0.01% (0.16% proof)
2^54761-174673 is Fermat and Lucas PRP! (170.3939s+0.0045s)

To be completed...