a(n) = A145818(2n-1).

Terms

a(0) =1a(1) =17a(2) =65a(3) =81a(4) =257a(5) =273a(6) =321a(7) =337a(8) =1025a(9) =1041a(10) =1089a(11) =1105a(12) =1281a(13) =1297a(14) =1345a(15) =1361a(16) =4097a(17) =4113a(18) =4161a(19) =4177a(20) =4353a(21) =4369a(22) =4417a(23) =4433a(24) =5121a(25) =5137a(26) =5185a(27) =5201a(28) =5377a(29) =5393