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

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =5a(10) =17a(11) =47a(12) =113a(13) =245a(14) =490a(15) =919a(16) =1634a(17) =2778a(18) =4546a(19) =7198a(20) =11074a(21) =16611a(22) =24363a(23) =35022a(24) =49443a(25) =68671a(26) =93971a(27) =126861a(28) =169148a(29) =222968