a(n) = prime(6*n - 2).

Terms

a(0) =7a(1) =29a(2) =53a(3) =79a(4) =107a(5) =139a(6) =173a(7) =199a(8) =239a(9) =271a(10) =311a(11) =349a(12) =383a(13) =421a(14) =457a(15) =491a(16) =541a(17) =577a(18) =613a(19) =647a(20) =683a(21) =733a(22) =769a(23) =821a(24) =857a(25) =887a(26) =941a(27) =983a(28) =1021a(29) =1061