Smallest primitive prime factor of 9^n-1.

Terms

a(0) =2a(1) =5a(2) =7a(3) =41a(4) =11a(5) =73a(6) =547a(7) =17a(8) =19a(9) =1181a(10) =23a(11) =6481a(12) =398581a(13) =29a(14) =31a(15) =21523361a(16) =103a(17) =530713a(18) =1597a(19) =42521761a(20) =43a(21) =5501a(22) =47a(23) =97a(24) =151a(25) =53a(26) =109a(27) =430697a(28) =59a(29) =47763361