Twin primes.

Terms

a(0) =3a(1) =5a(2) =7a(3) =11a(4) =13a(5) =17a(6) =19a(7) =29a(8) =31a(9) =41a(10) =43a(11) =59a(12) =61a(13) =71a(14) =73a(15) =101a(16) =103a(17) =107a(18) =109a(19) =137a(20) =139a(21) =149a(22) =151a(23) =179a(24) =181a(25) =191a(26) =193a(27) =197a(28) =199a(29) =227