Largest prime factor of 8^n - 1.

Terms

a(0) =7a(1) =7a(2) =73a(3) =13a(4) =151a(5) =73a(6) =337a(7) =241a(8) =262657a(9) =331a(10) =599479a(11) =109a(12) =121369a(13) =5419a(14) =23311a(15) =673a(16) =131071a(17) =262657a(18) =1212847a(19) =1321a(20) =649657a(21) =599479a(23) =38737a(24) =10567201a(25) =22366891a(26) =97685839a(27) =14449a(29) =18837001a(31) =22253377