A043478 Numbers n such that number of 6's in base 9 is 2.

60, 141, 222, 303, 384, 465, 492, 501, 510, 519, 528, 537, 540, 541, 542, 543, 544, 545, 547, 548, 555, 564, 627, 708, 789, 870, 951, 1032, 1113, 1194, 1221, 1230, 1239, 1248, 1257, 1266, 1269, 1270, 1271, 1272, 1273, 1274, 1276