Found with PFGW Version 3.7.5

50^31891-49 is 2-PRP! (24.5693s+0.0025s)
50^31891-49 is 3-PRP! (25.0746s+0.0024s)
50^31891-49 is 5-PRP! (24.7200s+0.0026s)
50^31891-49 is 7-PRP! (24.5490s+0.0025s)
50^31891-49 is 11-PRP! (25.1840s+0.0025s)

Primality testing 50^31891-49 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N+1 test using discriminant 7, base 6+sqrt(7)
Calling N-1 BLS with factored part 0.17% and helper 0.02% (0.52% proof)
50^31891-49 is Fermat and Lucas PRP! (203.6378s+0.0025s)

To be completed...