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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 12 |
| 5 | 20 |
| 6 | 21 |
| 7 | 100 |
| 8 | 101 |
| 9 | 102 |
| 10 | 112 |
| 11 | 121 |
| 12 | 122 |
| 13 | 201 |
| 14 | 202 |
| 15 | 210 |
| 16 | 211 |
| 17 | 212 |
| 18 | 220 |
| 19 | 221 |
| 20 | 222 |
| 21 | 1000 |
| 22 | 1001 |
| 23 | 1002 |
| 24 | 1011 |
| 25 | 1012 |
| 26 | 1021 |
| 27 | 1022 |
| 28 | 1100 |
| 29 | 1102 |
| 30 | 1110 |
| 31 | 1111 |
| 32 | 1112 |
| 33 | 1120 |
| 34 | 1121 |
| 35 | 1122 |
| 36 | 1200 |
| 37 | 1202 |
| 38 | 1210 |
| 39 | 1211 |
| 40 | 1212 |
| 41 | 1220 |
| 42 | 1221 |
| 43 | 1222 |
| 44 | 2010 |
| 45 | 2020 |
| 46 | 2021 |
| 47 | 2101 |
[1,2,10,12,20,21,100,101,102,112,121,122,201,202, 210,211,212,220,221,222,1000,1001,1002,1011,1012, 1021,1022,1100,1102,1110,1111,1112,1120,1121,1122, 1200,1202,1210,1211,1212,1220,1221,1222,2010,2020, 2021,2101] |