A048010 Number of nonempty subsets of {1,2,...,n} in which exactly 1/5 of the elements are <= (n-1)/3.

0, 0, 0, 0, 1, 5, 10, 30, 70, 105, 213, 405, 558, 1110, 2310, 3300, 7435, 16575, 23855, 52871, 113815, 160615, 346745, 744345, 1047438, 2299998, 5036862, 7110522, 15770601, 34636245, 48767082, 107787262, 236331302, 331877557