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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 37 |
| 5 | 730 |
| 6 | 29864 |
| 7 | 2491566 |
| 8 | 419695572 |
| 9 | 141865760710 |
| 10 | 95854674462202 |
[1,1,4,37,730,29864,2491566,419695572, 141865760710,95854674462202] |