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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 234 |
| 4 | 11934 |
| 5 | 1002456 |
| 6 | 125307000 |
| 7 | 21803418000 |
| 8 | 5036589558000 |
| 9 | 1490830509168000 |
| 10 | 550116457882992000 |
| 11 | 247552406047346400000 |
| 12 | 133430746859519709600000 |
| 13 | 84861955002654535305600000 |
| 14 | 62882708656967010661449600000 |
| 15 | 53701833193049827104877958400000 |
[1,9,234,11934,1002456,125307000,21803418000, 5036589558000,1490830509168000,550116457882992000, 247552406047346400000,133430746859519709600000, 84861955002654535305600000, 62882708656967010661449600000, 53701833193049827104877958400000] |