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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 81 |
| 6 | 331776 |
| 7 | 10754830178 |
| 8 | 257119084477153 |
| 9 | 5819786432246732561 |
[1,1,1,1,81,331776,10754830178,257119084477153, 5819786432246732561] |