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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | -6 |
| 3 | -24 |
| 4 | -104 |
| 5 | -530 |
| 6 | -3192 |
| 7 | -22358 |
| 8 | -178880 |
| 9 | -1609938 |
| 10 | -16099400 |
| 11 | -177093422 |
| 12 | -2125121088 |
| 13 | -27626574170 |
| 14 | -386772038408 |
| 15 | -5801580576150 |
| 16 | -92825289218432 |
| 17 | -1578029916713378 |
| 18 | -28404538500840840 |
[1,-1,-6,-24,-104,-530,-3192,-22358,-178880, -1609938,-16099400,-177093422,-2125121088, -27626574170,-386772038408,-5801580576150, -92825289218432,-1578029916713378, -28404538500840840] |