Found with PFGW Version 3.8.0

983^10988-10988^983 is 2-PRP! (20.7896s+0.0051s)
983^10988-10988^983 is 3-PRP! (20.8024s+0.0065s)
983^10988-10988^983 is 5-PRP! (20.8643s+0.0132s)
983^10988-10988^983 is 7-PRP! (21.3114s+0.0062s)
983^10988-10988^983 is 11-PRP! (20.8943s+0.0059s)

Primality testing 983^10988-10988^983 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N+1 test using discriminant 7, base 1+sqrt(7)
Calling N-1 BLS with factored part 0.03% and helper 0.01% (0.10% proof)
983^10988-10988^983 is Fermat and Lucas PRP! (107.4214s+0.0065s)

To be completed...