Found with PFGW Version 3.7.5

2540^6429-6429^2540 is 2-PRP! (16.9175s+0.0029s)
2540^6429-6429^2540 is 3-PRP! (17.4764s+0.0026s)
2540^6429-6429^2540 is 5-PRP! (18.9599s+0.0020s)
2540^6429-6429^2540 is 7-PRP! (22.5117s+0.0020s)
2540^6429-6429^2540 is 11-PRP! (18.0552s+0.0024s)

Primality testing 2540^6429-6429^2540 [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 0.06% and helper 0.02% (0.19% proof)
2540^6429-6429^2540 is Fermat and Lucas PRP! (87.1763s+0.0042s)

To be completed...