A047190 - OEIS

A047190

Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-2)/2.

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

%S 0,0,0,0,0,0,0,0,0,6,7,35,40,120,135,315,350,745,825,1881,2106,5490,

%T 6240,17160,19635,52339,59855,151775,173160,427336,487305,1207765,

%U 1380405,3490050

%N Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-2)/2.

%K nonn

%O 1,10

%A _Clark Kimberling_