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

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =4a(5) =5a(6) =6a(7) =27a(8) =35a(9) =44a(10) =164a(11) =219a(12) =285a(13) =1000a(14) =1364a(15) =1819a(16) =6187a(17) =8567a(18) =11627a(19) =38759a(20) =54263a(21) =74612a(22) =245156a(23) =346103a(24) =480699a(25) =1562274a(26) =2220074a(27) =3108104a(28) =10015004a(29) =14307149