a(n)=a(n-1)+2*a(n-2)-[a(n-1)/2]-[a(n-4)/2]-[a(n-5)/2].

Terms

a(0) =1a(1) =1a(2) =3a(3) =4a(4) =8a(5) =12a(6) =21a(7) =32a(8) =52a(9) =80a(10) =128a(11) =198a(12) =313a(13) =487a(14) =766a(15) =1194a(16) =1874a(17) =2926a(18) =4585a(19) =7165a(20) =11219a(21) =17540a(22) =27453a(23) =42933a(24) =67182a(25) =105078a(26) =164407a(27) =257168a(28) =402341a(29) =629377