Largest prime factor of 8^n + 1.

Terms

a(0) =2a(1) =3a(2) =13a(3) =19a(4) =241a(5) =331a(6) =109a(7) =5419a(8) =673a(9) =87211a(10) =1321a(11) =20857a(12) =38737a(13) =22366891a(14) =14449a(15) =18837001a(16) =22253377a(17) =43691a(18) =279073a(19) =160465489a(20) =4562284561a(21) =77158673929a(22) =4327489a(23) =168749965921a(24) =487824887233a(26) =21841a(27) =272010961a(28) =88959882481