a(n) = 9*n + 6.

Terms

a(0) =6a(1) =15a(2) =24a(3) =33a(4) =42a(5) =51a(6) =60a(7) =69a(8) =78a(9) =87a(10) =96a(11) =105a(12) =114a(13) =123a(14) =132a(15) =141a(16) =150a(17) =159a(18) =168a(19) =177a(20) =186a(21) =195a(22) =204a(23) =213a(24) =222a(25) =231a(26) =240a(27) =249a(28) =258a(29) =267