a(n) = Sum_{k=0..floor(n/2)} (k+1) * binomial(k,2*(n-2*k)).

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =3a(5) =3a(6) =4a(7) =12a(8) =5a(9) =30a(10) =11a(11) =60a(12) =37a(13) =105a(14) =113a(15) =175a(16) =289a(17) =308a(18) =640a(19) =612a(20) =1280a(21) =1335a(22) =2412a(23) =2970a(24) =4468a(25) =6413a(26) =8429a(27) =13236a(28) =16460a(29) =26247