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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 18 |
| 4 | 180 |
| 5 | 1800 |
| 6 | 18000 |
| 7 | 180000 |
| 8 | 1800000 |
| 9 | 18000000 |
| 10 | 180000000 |
| 11 | 1800000000 |
| 12 | 18000000000 |
| 13 | 180000000000 |
| 14 | 1800000000000 |
| 15 | 18000000000000 |
| 16 | 180000000000000 |
| 17 | 1800000000000000 |
| 18 | 18000000000000000 |
| 19 | 180000000000000000 |
| 20 | 1800000000000000000 |
| 21 | 18000000000000000000 |
| 22 | 180000000000000000000 |
[0,2,18,180,1800,18000,180000,1800000,18000000, 180000000,1800000000,18000000000,180000000000, 1800000000000,18000000000000,180000000000000, 1800000000000000,18000000000000000, 180000000000000000,1800000000000000000, 18000000000000000000,180000000000000000000] |