PRP de base 3. Fermat et Lucas PRP.

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

Primality testing 21^193601-20^193601 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N+1 test using discriminant 19, base 1+sqrt(19)
Calling N-1 BLS with factored part 0.02% and helper 0.00% (0.06% proof) 21^193601-20^193601 is Fermat and Lucas PRP! (23495.8165s+0.0046s)

To be completed...