A048012 Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= (n-1)/3.

0, 0, 0, 0, 0, 0, 0, 0, 0, 21, 28, 36, 144, 180, 220, 550, 660, 780, 2275, 2821, 3465, 13230, 16940, 21420, 74256, 94248, 118104, 367080, 461700, 574644, 1824690, 2310000, 2899380, 9684840, 12357532, 15634300, 51798175, 66098175