Found with PFGW Version 3.7.5

263^20718-20718^263 is 2-PRP! (47.4963s+0.0026s)
263^20718-20718^263 is 3-PRP! (46.7680s+0.0025s)
263^20718-20718^263 is 5-PRP! (46.6743s+0.0026s)
263^20718-20718^263 is 7-PRP! (46.5506s+0.0027s)
263^20718-20718^263 is 11-PRP! (46.6225s+0.0026s)

Primality testing 263^20718-20718^263 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Running N-1 test using base 7
Running N+1 test using discriminant 13, base 8+sqrt(13)
Calling N-1 BLS with factored part 0.00% and helper 0.00% (0.02% proof)
263^20718-20718^263 is Fermat and Lucas PRP! (332.1527s+0.0032s)

To be completed...