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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 6 |
| 4 | -18 |
| 5 | 135 |
| 6 | -795 |
| 7 | 7266 |
| 8 | -62188 |
| 9 | 669309 |
| 10 | -7267005 |
| 11 | 90797894 |
| 12 | -1179693966 |
| 13 | 16915574299 |
| 14 | -254880171455 |
| 15 | 4143992814482 |
| 16 | -70922672184120 |
| 17 | 1292106133397017 |
| 18 | -24733436584847481 |
| 19 | 499532815860896038 |
[0,1,-1,6,-18,135,-795,7266,-62188,669309, -7267005,90797894,-1179693966,16915574299, -254880171455,4143992814482,-70922672184120, 1292106133397017,-24733436584847481, 499532815860896038] |