a(n) = T(n, floor(n/2)), T given by A026769.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =17a(6) =28a(7) =76a(8) =120a(9) =352a(10) =538a(11) =1674a(12) =2493a(13) =8129a(14) =11854a(15) =40156a(16) =57558a(17) =201236a(18) =284392a(19) =1020922a(20) =1426038a(21) =5234660a(22) =7241356a(23) =27089726a(24) =37173304a(25) =141335846a(26) =192638992a(27) =742712598a(28) =1006564439a(29) =3927908193