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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | -3 |
| 4 | 40 |
| 5 | -795 |
| 6 | 22896 |
| 7 | -877625 |
| 8 | 42472704 |
| 9 | -2504024775 |
| 10 | 175277668960 |
| 11 | -14288006295189 |
| 12 | 1336079557627200 |
| 13 | -141604073759908331 |
| 14 | 16843101697284562896 |
| 15 | -2230002746655974502225 |
| 16 | 326367650557985432023936 |
| 17 | -52485113772229506638866575 |
| 18 | 9226584510326784965254184640 |
| 19 | -1764994657079434895818835078573 |
[1,2,-3,40,-795,22896,-877625,42472704, -2504024775,175277668960,-14288006295189, 1336079557627200,-141604073759908331, 16843101697284562896,-2230002746655974502225, 326367650557985432023936, -52485113772229506638866575, 9226584510326784965254184640, -1764994657079434895818835078573] |