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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 35 |
| 5 | 473 |
| 6 | 11280 |
| 7 | 494579 |
| 8 | 44461736 |
| 9 | 7927841482 |
| 10 | 2782301025984 |
| 11 | 1928382976203757 |
[1,2,7,35,473,11280,494579,44461736,7927841482, 2782301025984,1928382976203757] |