a(n) = binomial(n, floor((n-7)/2)).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =1a(9) =9a(10) =10a(11) =55a(12) =66a(13) =286a(14) =364a(15) =1365a(16) =1820a(17) =6188a(18) =8568a(19) =27132a(20) =38760a(21) =116280a(22) =170544a(23) =490314a(24) =735471a(25) =2042975a(26) =3124550a(27) =8436285a(28) =13123110a(29) =34597290