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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =7a(8) =8a(9) =9a(10) =10a(11) =11a(12) =12a(13) =13a(14) =91a(15) =105a(16) =120a(17) =136a(18) =153a(19) =171a(20) =190a(21) =1330a(22) =1540a(23) =1771a(24) =2024a(25) =2300a(26) =2600a(27) =2925a(28) =20475a(29) =23751