1st PRP for 2^n-437609.

Sieved to P=200G.

Primality testing 2^153876-437609 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 43
Running N+1 test using discriminant 71, base 1+sqrt(71)
Calling N-1 BLS with factored part 0.01% and helper 0.00% (0.04% proof)
2^153876-437609 is Fermat and Lucas PRP! (2449.9985s+0.0058s)

To be completed...