Lucky numbers.

Terms

a(0) =1a(1) =3a(2) =7a(3) =9a(4) =13a(5) =15a(6) =21a(7) =25a(8) =31a(9) =33a(10) =37a(11) =43a(12) =49a(13) =51a(14) =63a(15) =67a(16) =69a(17) =73a(18) =75a(19) =79a(20) =87a(21) =93a(22) =99a(23) =105a(24) =111a(25) =115a(26) =127a(27) =129a(28) =133a(29) =135