%I #7 Apr 16 2019 15:07:14
%S 0,0,0,0,0,0,0,0,0,0,7,8,9,45,50,55,165,180,195,455,490,525,1155,1240,
%T 1326,3366,3645,3933,11685,12750,13860,41580,45375,49335,138391,
%U 150524,163175,433875,470665,509067,1347255,1461278,1580761
%N Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n+1)/3.
%H Robert Israel, <a href="/A048046/b048046.txt">Table of n, a(n) for n = 1..5710</a>
%p f:= proc(n) local k,j;
%p k:= floor((n+1)/3);
%p add(binomial(k,4/5*j)*binomial(n-k,1/5*j),j=5..n,5)
%p end proc:
%p map(f, [$1..100]); # _Robert Israel_, Apr 16 2019
%K nonn
%O 1,11
%A _Clark Kimberling_