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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 205 |
| 4 | 17108 |
| 5 | 4693632 |
| 6 | 4253751084 |
| 7 | 12768573248145 |
| 8 | 127147160484338304 |
| 9 | 4204352991963054866432 |
[1,8,205,17108,4693632,4253751084,12768573248145, 127147160484338304,4204352991963054866432] |