Smallest odd prime factor of 3^n + 1, for n > 1.

Terms

a(0) =5a(1) =7a(2) =41a(3) =61a(4) =5a(5) =547a(6) =17a(7) =7a(8) =5a(9) =67a(10) =41a(11) =398581a(12) =5a(13) =7a(14) =21523361a(15) =103a(16) =5a(17) =2851a(18) =41a(19) =7a(20) =5a(21) =23535794707a(22) =17a(23) =61a(24) =5a(25) =7a(26) =41a(27) =523a(28) =5a(29) =6883