A166019 Right edge of triangular table A138612.
1, 4, 12, 28, 53, 91, 141, 207, 297, 401, 534, 683, 869, 1081, 1327, 1601, 1912, 2275, 2665, 3095, 3569, 4110, 4682, 5314, 5996, 6744, 7535, 8394, 9320, 10303, 11367, 12490, 13686, 14938, 16288, 17707, 19227, 20808, 22490, 24233, 26103, 28033
Offset: 1