a(2*n) = 3*2^n - 2; a(2*n+1) = 2^(n+2) - 2.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =14a(6) =22a(7) =30a(8) =46a(9) =62a(10) =94a(11) =126a(12) =190a(13) =254a(14) =382a(15) =510a(16) =766a(17) =1022a(18) =1534a(19) =2046a(20) =3070a(21) =4094a(22) =6142a(23) =8190a(24) =12286a(25) =16382a(26) =24574a(27) =32766a(28) =49150a(29) =65534