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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 72 |
| 5 | 1045 |
| 6 | 34736 |
| 7 | 2260659 |
| 8 | 267327524 |
| 9 | 64601028921 |
| 10 | 30441597686957 |
[1,1,7,72,1045,34736,2260659,267327524, 64601028921,30441597686957] |