Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-3)/3.

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) =0a(14) =0a(15) =0a(16) =0a(17) =13a(18) =14a(19) =15a(20) =90a(21) =96a(22) =102a(23) =357a(24) =378a(25) =399a(26) =1064a(27) =1120a(28) =1176a(29) =2646