1st PRP for 2^n-254233.

Sieved to P=200G.

Primality testing 2^188857-254233 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 29
Running N+1 test using discriminant 41, base 1+sqrt(41)
Calling N-1 BLS with factored part 0.01% and helper 0.00% (0.03% proof)
2^188857-254233 is Fermat and Lucas PRP! (1117.9299s+0.0002s)

To be completed...