Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-4)/2.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =0a(10) =0a(11) =0a(12) =0a(13) =9a(14) =10a(15) =60a(16) =66a(17) =231a(18) =252a(19) =672a(20) =728a(21) =1638a(22) =1764a(23) =3619a(24) =3885a(25) =8085a(26) =8712a(27) =20592a(28) =22440a(29) =60775