a(n) = prime(7*n - 5).

Terms

a(0) =3a(1) =23a(2) =53a(3) =83a(4) =113a(5) =157a(6) =193a(7) =233a(8) =271a(9) =313a(10) =359a(11) =401a(12) =443a(13) =487a(14) =541a(15) =587a(16) =619a(17) =661a(18) =719a(19) =761a(20) =821a(21) =859a(22) =911a(23) =967a(24) =1013a(25) =1051a(26) =1097a(27) =1153a(28) =1213a(29) =1259