a(n) = T(n, floor(n/2)), where T is given by A026584.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =8a(6) =19a(7) =22a(8) =69a(9) =121a(10) =341a(11) =406a(12) =1203a(13) =2155a(14) =6336a(15) =7624a(16) =22593a(17) =40717a(18) =121483a(19) =147001a(20) =438533a(21) =792351a(22) =2381512a(23) =2892044a(24) =8677763a(25) =15703156a(26) =47419503a(27) =57728737a(28) =173984792a(29) =315180458