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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | -2 |
| 4 | 48 |
| 5 | 30240 |
| 6 | -1596672000 |
| 7 | -18172937502720000 |
| 8 | 122457316443772566896640000 |
| 9 | 1284319496829094129116119090331648000000 |
| 10 | -55603466527142141932748234118927499493985767915520000000 |
[1,-1,-2,48,30240,-1596672000,-18172937502720000, 122457316443772566896640000, 1284319496829094129116119090331648000000, -5560346652714214193274823411892749949398576791552\ 0000000] |