Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-2)/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) =7a(12) =8a(13) =48a(14) =54a(15) =189a(16) =210a(17) =560a(18) =616a(19) =1386a(20) =1512a(21) =3090a(22) =3354a(23) =6864a(24) =7469a(25) =17094a(26) =18810a(27) =49335a(28) =54912a(29) =152152