A231870 - OEIS

A231870 as a simple table

n	a(n)
1	1
2	11
3	12
4	13
5	111
6	112
7	113
8	121
9	122
10	123
11	124
12	131
13	132
14	133
15	134
16	135
17	1111
18	1112
19	1113
20	1121
21	1122
22	1123
23	1124
24	1131
25	1132
26	1133
27	1134
28	1135
29	1211
30	1212
31	1213
32	1221
33	1222
34	1223
35	1224
36	1231
37	1232
38	1233
39	1234
40	1235
41	1241
42	1242
43	1243
44	1244
45	1245
46	1246
47	1311
48	1312
49	1313
50	1321
51	1322
52	1323
53	1324
54	1331
55	1332
56	1333
57	1334

[1,11,12,13,111,112,113,121,122,123,124,131,132, 133,134,135,1111,1112,1113,1121,1122,1123,1124, 1131,1132,1133,1134,1135,1211,1212,1213,1221,1222, 1223,1224,1231,1232,1233,1234,1235,1241,1242,1243, 1244,1245,1246,1311,1312,1313,1321,1322,1323,1324, 1331,1332,1333,1334]