a(n) = 5*n + 2.

Terms

a(0) =2a(1) =7a(2) =12a(3) =17a(4) =22a(5) =27a(6) =32a(7) =37a(8) =42a(9) =47a(10) =52a(11) =57a(12) =62a(13) =67a(14) =72a(15) =77a(16) =82a(17) =87a(18) =92a(19) =97a(20) =102a(21) =107a(22) =112a(23) =117a(24) =122a(25) =127a(26) =132a(27) =137a(28) =142a(29) =147