Largest prime factor of 5^n - 2^n.
3, 7, 13, 29, 1031, 19, 25999, 641, 5563, 1031, 11551, 541, 406898311, 25999, 8161, 22993, 3101039, 5563, 6357828601279, 5521, 25999, 303293, 2650751, 380881, 6660751, 406898311, 1271899175923, 210466621, 40269058729, 508771, 4161405605965366483
1
T. D. Noe, Plot of 100 terms
T. D. Noe, Table of 100 terms
Eric W. Weisstein, MathWorld: Greatest Prime Factor
(Mma) Table[FactorInteger[5^n - 2^n][[-1, 1]], {n, 40}]
nonn
T. D. Noe, Jun 08 2015