Start with 1, then alternately double or add 2.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =10a(5) =20a(6) =22a(7) =44a(8) =46a(9) =92a(10) =94a(11) =188a(12) =190a(13) =380a(14) =382a(15) =764a(16) =766a(17) =1532a(18) =1534a(19) =3068a(20) =3070a(21) =6140a(22) =6142a(23) =12284a(24) =12286a(25) =24572a(26) =24574a(27) =49148a(28) =49150a(29) =98300