Smallest primitive prime factor of 7^n-1.

Terms

a(0) =2a(1) =1a(2) =19a(3) =5a(4) =2801a(5) =43a(6) =29a(7) =1201a(8) =37a(9) =11a(10) =1123a(11) =13a(12) =16148168401a(13) =113a(14) =31a(15) =17a(16) =14009a(17) =117307a(18) =419a(19) =281a(20) =11898664849a(21) =23a(22) =47a(23) =73a(24) =2551a(25) =53a(26) =109a(27) =13564461457a(28) =59a(29) =6568801