A166375 a(n) = sum (floor (j^2/n)) taken over 1 <= j <= n-1, with n >= 2.

0, 1, 3, 4, 7, 11, 16, 20, 24, 31, 39, 44, 53, 63, 74, 80, 92, 103, 117, 128, 141, 157, 174, 186, 200, 219, 237, 252, 273, 293, 316, 332, 352, 377, 403, 420, 445, 473, 500, 520, 548, 575, 607, 634, 663, 695, 730, 756, 786, 819, 853, 884, 921, 959, 998