A048074 - OEIS

%I #4 Mar 30 2012 18:56:54

%S 0,0,0,0,2,8,12,30,63,86,182,392,560,1270,2800,4070,9020,19595,28679,

%T 63518,138866,205478,455966,997640,1485624,3290520,7201692,10782222,

%U 23878212,52311408,78678468,174179258,381766253,576312440

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

%K nonn

%O 1,5

%A _Clark Kimberling_