a(n) = floor( binomial(n,8)/9).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =1a(10) =5a(11) =18a(12) =55a(13) =143a(14) =333a(15) =715a(16) =1430a(17) =2701a(18) =4862a(19) =8398a(20) =13996a(21) =22610a(22) =35530a(23) =54479a(24) =81719a(25) =120175a(26) =173586a(27) =246675a(28) =345345a(29) =476905