Largest prime factor of 7^n - 2^n.
5, 5, 67, 53, 61, 67, 164683, 2417, 739, 1871, 1987261, 2221, 14894543, 164683, 136261, 339121, 766606297, 2017, 2279779036969771, 5329741, 235448977, 9552313, 116462754638606501, 16993, 158305897173001, 14894543, 2409792661, 164683
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[7^n - 2^n][[-1, 1]], {n, 40}]
nonn
T. D. Noe, Jun 08 2015