a(n) = a(n-3) + 2^(n-4) with a(1) = 1, a(2) = 2, a(3) = 1.

Terms

a(0) =1a(1) =2a(2) =1a(3) =2a(4) =4a(5) =5a(6) =10a(7) =20a(8) =37a(9) =74a(10) =148a(11) =293a(12) =586a(13) =1172a(14) =2341a(15) =4682a(16) =9364a(17) =18725a(18) =37450a(19) =74900a(20) =149797a(21) =299594a(22) =599188a(23) =1198373a(24) =2396746a(25) =4793492a(26) =9586981a(27) =19173962a(28) =38347924a(29) =76695845