A119104 Numbers n such that the n-th triangular number contains only digits {1,2,6}.

1, 3, 6, 11, 36, 66, 111, 651, 666, 1563, 1588, 5766, 6651, 6666, 15563, 15888, 36366, 65766, 66651, 66666, 205748, 363666, 576406, 657666, 666651, 666666, 6657666, 6666651, 6666666, 18014806, 36394123, 66576666, 66666651, 66666666