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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 18 |
| 5 | 234 |
| 6 | 279 |
| 7 | 1278 |
| 8 | 1566 |
| 9 | 13689 |
| 10 | 4599 |
| 11 | 114777 |
| 12 | 113445 |
| 13 | 1233459 |
| 14 | 2467899 |
| 15 | 1344789 |
| 16 | 1234467 |
| 17 | 11123469 |
| 18 | 23447889 |
| 19 | 1112246667 |
| 20 | 134446788 |
| 21 | 12333456 |
| 22 | 113356899 |
| 23 | 11234477889 |
| 24 | 122234456889 |
| 25 | 23444678889 |
| 26 | 1222345568889 |
| 27 | 2445567778899 |
[1,3,9,27,18,234,279,1278,1566,13689,4599,114777, 113445,1233459,2467899,1344789,1234467,11123469, 23447889,1112246667,134446788,12333456,113356899, 11234477889,122234456889,23444678889, 1222345568889,2445567778899] |