a(n) = floor(binomial(n,7)/8).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =4a(10) =15a(11) =41a(12) =99a(13) =214a(14) =429a(15) =804a(16) =1430a(17) =2431a(18) =3978a(19) =6298a(20) =9690a(21) =14535a(22) =21318a(23) =30644a(24) =43263a(25) =60087a(26) =82225a(27) =111003a(28) =148005a(29) =195097