Found with PFGW Version 3.5.2

1878^3553-3553^1878 is 2-PRP! (13.3169s+0.0169s)
1878^3553-3553^1878 is 3-PRP! (13.0396s+0.0049s)
1878^3553-3553^1878 is 5-PRP! (22.6188s+0.0063s)
1878^3553-3553^1878 is 7-PRP! (26.4005s+0.0064s)
1878^3553-3553^1878 is 11-PRP! (13.0198s+0.0050s)

Primality testing 1878^3553-3553^1878 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 7
Running N+1 test using discriminant 13, base 1+sqrt(13)
Calling N-1 BLS with factored part 0.03% and helper 0.03% (0.13% proof)
1878^3553-3553^1878 is Fermat and Lucas PRP! (148.6018s+0.0129s)

To be completed...