Odd nonprimes.

Terms

a(0) =1a(1) =9a(2) =15a(3) =21a(4) =25a(5) =27a(6) =33a(7) =35a(8) =39a(9) =45a(10) =49a(11) =51a(12) =55a(13) =57a(14) =63a(15) =65a(16) =69a(17) =75a(18) =77a(19) =81a(20) =85a(21) =87a(22) =91a(23) =93a(24) =95a(25) =99a(26) =105a(27) =111a(28) =115a(29) =117