a(n) = a(n-1) + a(n-2) - [a(n-2)/4] - [a(n-4)/2] - [a(n-6)/4].

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =5a(5) =8a(6) =11a(7) =16a(8) =23a(9) =31a(10) =43a(11) =57a(12) =77a(13) =101a(14) =133a(15) =174a(16) =226a(17) =293a(18) =378a(19) =486a(20) =624a(21) =800a(22) =1023a(23) =1307a(24) =1669a(25) =2129a(26) =2714a(27) =3458a(28) =4405a(29) =5609