Largest prime factor of 6^n + 1.

Terms

a(0) =2a(1) =7a(2) =37a(3) =31a(4) =1297a(5) =101a(6) =97a(7) =197a(8) =98801a(9) =46441a(10) =6781a(11) =51828151a(12) =1678321a(13) =37571a(14) =5030761a(15) =1950271a(16) =4709377a(17) =12690943a(18) =55117a(19) =48713705333a(20) =68754507401a(21) =2527867231a(22) =863017a(23) =990000731a(24) =473896897a(27) =883383463a(28) =81035189089