%I

%S 0,0,0,0,2,3,12,30,40,86,182,245,560,1270,1784,4070,9020,12782,28679,

%T 63518,91286,205478,455966,662151,1485624,3290520,4814672,10782222,

%U 23878212,35172819,78678468,174179258,257964134,576312440

%N Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n+3)/3.

%K nonn

%O 1,5

%A _Clark Kimberling_