PRP de base 3. Fermat and Lucas PRP.

PFGW Version 3.7.7.64BIT.20130722.x86_Dev [GWNUM 27.11]

Primality testing 21^176191-20^176191 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N-1 test using base 17
Running N+1 test using discriminant 23, base 1+sqrt(23)
Calling N-1 BLS with factored part 0.02% and helper 0.00% (0.05% proof) 21^176191-20^176191 is Fermat and Lucas PRP! (20004.8453s+0.0040s)

To be completed...