Found with PFGW Version 3.6.0

920^3923-3923^920 is 2-PRP! (5.8696s+0.0018s)
920^3923-3923^920 is 3-PRP! (5.7734s+0.0016s)
920^3923-3923^920 is 5-PRP! (5.8301s+0.0015s)
920^3923-3923^920 is 7-PRP! (5.7705s+0.0016s)
920^3923-3923^920 is 11-PRP! (5.7306s+0.0018s)

Primality testing 920^3923-3923^920 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N+1 test using discriminant 11, base 1+sqrt(11)
Calling N-1 BLS with factored part 0.12% and helper 0.07% (0.44% proof)
920^3923-3923^920 is Fermat and Lucas PRP! (30.6547s+0.0015s)

To be completed...