a(0) = a(1) = 1; for n > 1, a(n) = Sum_{k=0..n-2} a(k) OR a(n-k-2).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =8a(6) =13a(7) =30a(8) =52a(9) =112a(10) =217a(11) =446a(12) =864a(13) =1750a(14) =3469a(15) =6976a(16) =13892a(17) =27828a(18) =55550a(19) =111158a(20) =222224a(21) =444458a(22) =888747a(23) =1777546a(24) =3554844a(25) =7109666a(26) =14218740a(27) =28437336a(28) =56874024a(29) =113747200