1st PRP for 2^n-320789.

Sieved to P=200G.

Primality testing 2^121816-320789 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Running N+1 test using discriminant 13, base 1+sqrt(13)
Calling N+1 BLS with factored part 0.03% and helper 0.01% (0.09% proof)
2^121816-320789 is Fermat and Lucas PRP! (1506.7539s+0.0059s)

To be completed...