a(n) = a(n-2) + a(n-3), with a(0) = 0, a(1) = 1, a(2) = 4.

Terms

a(0) =0a(1) =1a(2) =4a(3) =1a(4) =5a(5) =5a(6) =6a(7) =10a(8) =11a(9) =16a(10) =21a(11) =27a(12) =37a(13) =48a(14) =64a(15) =85a(16) =112a(17) =149a(18) =197a(19) =261a(20) =346a(21) =458a(22) =607a(23) =804a(24) =1065a(25) =1411a(26) =1869a(27) =2476a(28) =3280a(29) =4345