%I #5 Mar 30 2012 18:56:53
%S 0,0,0,0,3,4,12,15,40,51,135,175,455,596,1540,2037,5250,7000,18000,
%T 24156,62007,83667,214467,290719,744315,1012935,2590679,3537703,
%U 9039823,12381252,31612324,43411489,110761494,152459010
%N Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= (n-1)/2.
%K nonn
%O 1,5
%A _Clark Kimberling_