a(n) = A026615(n, floor(n/2)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =5a(4) =10a(5) =17a(6) =34a(7) =60a(8) =120a(9) =217a(10) =434a(11) =798a(12) =1596a(13) =2970a(14) =5940a(15) =11154a(16) =22308a(17) =42185a(18) =84370a(19) =160446a(20) =320892a(21) =613054a(22) =1226108a(23) =2351440a(24) =4702880a(25) =9048522a(26) =18097044a(27) =34916300a(28) =69832600a(29) =135059220