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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 3 |
| 4 | 80 |
| 5 | 1637 |
| 6 | 18775 |
| 7 | 1841903 |
| 8 | 326461365 |
| 9 | 50773963070 |
| 10 | 27507422939178 |
[1,4,3,80,1637,18775,1841903,326461365, 50773963070,27507422939178] |