a(n) = binomial(n, floor((n-8)/2)).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =1a(10) =10a(11) =11a(12) =66a(13) =78a(14) =364a(15) =455a(16) =1820a(17) =2380a(18) =8568a(19) =11628a(20) =38760a(21) =54264a(22) =170544a(23) =245157a(24) =735471a(25) =1081575a(26) =3124550a(27) =4686825a(28) =13123110a(29) =20030010