a(n) = floor( binomial(n,9)/10 ).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =0a(10) =1a(11) =5a(12) =22a(13) =71a(14) =200a(15) =500a(16) =1144a(17) =2431a(18) =4862a(19) =9237a(20) =16796a(21) =29393a(22) =49742a(23) =81719a(24) =130750a(25) =204297a(26) =312455a(27) =468682a(28) =690690a(29) =1001500