A047174 - OEIS

%I #5 Mar 30 2012 18:56:53

%S 0,0,0,1,2,8,12,30,40,86,110,245,315,756,980,2387,3080,7400,9480,

%T 22737,29040,70390,89870,219791,280423,688051,876603,2154347,2741102,

%U 6754580,8586788,21225758,26965808,66826712

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

%K nonn

%O 1,5

%A _Clark Kimberling_