a(n) = a(n-2)+a(n-3) with a(1)=2 a(2)=1 a(3)=0.

Terms

a(0) =2a(1) =1a(2) =0a(3) =3a(4) =1a(5) =3a(6) =4a(7) =4a(8) =7a(9) =8a(10) =11a(11) =15a(12) =19a(13) =26a(14) =34a(15) =45a(16) =60a(17) =79a(18) =105a(19) =139a(20) =184a(21) =244a(22) =323a(23) =428a(24) =567a(25) =751a(26) =995a(27) =1318a(28) =1746a(29) =2313