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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 11 |
| 4 | 80 |
| 5 | 780 |
| 6 | 8781 |
| 7 | 104828 |
| 8 | 1298506 |
| 9 | 16462696 |
| 10 | 212457221 |
| 11 | 2780615627 |
| 12 | 36817036777 |
[1,2,11,80,780,8781,104828,1298506,16462696, 212457221,2780615627,36817036777] |