Found with PFGW Version 3.6.0

3104^3921-3921^3104 is 2-PRP! (8.9396s+0.0031s)
3104^3921-3921^3104 is 3-PRP! (9.1194s+0.0019s)
3104^3921-3921^3104 is 5-PRP! (9.2178s+0.0018s)
3104^3921-3921^3104 is 7-PRP! (9.1524s+0.0032s)
3104^3921-3921^3104 is 11-PRP! (9.1278s+0.0030s)

Primality testing 3104^3921-3921^3104 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Running N+1 test using discriminant 11, base 2+sqrt(11)
Calling N-1 BLS with factored part 0.14% and helper 0.03% (0.46% proof)
3104^3921-3921^3104 is Fermat and Lucas PRP! (42.7100s+0.0031s)

To be completed...