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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | -1 |
| 3 | -3 |
| 4 | -38 |
| 5 | -135 |
| 6 | -4315 |
| 7 | -48125 |
| 8 | -950684 |
| 9 | -7217406 |
| 10 | -682590930 |
| 11 | -6554931075 |
| 12 | -903921420138 |
| 13 | -10496162430897 |
| 14 | -132415122967127 |
| 15 | -3606726811032345 |
| 16 | -896549281211592008 |
| 17 | -14008671728814262500 |
| 18 | -4425739007479443851340 |
[1,-1,-1,-3,-38,-135,-4315,-48125,-950684, -7217406,-682590930,-6554931075,-903921420138, -10496162430897,-132415122967127, -3606726811032345,-896549281211592008, -14008671728814262500,-4425739007479443851340] |