A048321 Reading a(n) expansion from left to right, run lengths strictly decrease.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 440, 441, 442, 443, 444, 445, 446, 447, 448