Primes of the form 3n-1.

Terms

a(0) =2a(1) =5a(2) =11a(3) =17a(4) =23a(5) =29a(6) =41a(7) =47a(8) =53a(9) =59a(10) =71a(11) =83a(12) =89a(13) =101a(14) =107a(15) =113a(16) =131a(17) =137a(18) =149a(19) =167a(20) =173a(21) =179a(22) =191a(23) =197a(24) =227a(25) =233a(26) =239a(27) =251a(28) =257a(29) =263