A028725 (1/12) floor(1/2 n) floor(1/2 n - 1/2) floor(1/2 n - 1) floor(1/2 n - 3/2) floor(1/2 n - 2).

0, 0, 0, 0, 0, 0, 1, 3, 12, 24, 60, 100, 200, 300, 525, 735, 1176, 1568, 2352, 3024, 4320, 5400, 7425, 9075, 12100, 14520, 18876, 22308, 28392, 33124, 41405, 47775, 58800, 67200, 81600, 92480, 110976