Largest prime factor of 9^n - 5^n.
2, 7, 151, 53, 41, 151, 40559, 3593, 33589, 4441, 7833057871, 397, 8040016219, 49603, 45061, 1277569, 4169104690053361, 455941, 40847631499, 32986321, 154016989561, 7833057871, 238120979, 39336721, 240151, 181649037961, 414702991, 1095819173
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[9^n - 5^n][[-1, 1]], {n, 40}]
nonn
T. D. Noe, Jun 08 2015