A047189 Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= (n-2)/2.

0, 0, 0, 0, 0, 0, 0, 10, 15, 60, 84, 210, 280, 630, 846, 2142, 3045, 8400, 12320, 32802, 48048, 121110, 176670, 437580, 642642, 1608607, 2391895, 6034600, 9050470, 22712326, 34185606, 84996158, 128251383, 317302008