1st PRP for 2^n-275591.

Sieved to P=200G.

Primality testing 2^61678-275591 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 47
Running N+1 test using discriminant 83, base 4+sqrt(83)
Calling N+1 BLS with factored part 0.05% and helper 0.04% (0.19% proof)
2^61678-275591 is Fermat and Lucas PRP! (177.4646s+0.0052s)

To be completed...