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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -2 |
| 2 | -3 |
| 3 | -1 |
| 4 | 3 |
| 5 | 3 |
| 6 | -9 |
| 7 | -17 |
| 8 | 51 |
| 9 | 155 |
| 10 | -465 |
| 11 | -2073 |
| 12 | 6219 |
| 13 | 38227 |
| 14 | -114681 |
| 15 | -929569 |
| 16 | 2788707 |
| 17 | 28820619 |
| 18 | -86461857 |
| 19 | -1109652905 |
| 20 | 3328958715 |
| 21 | 51943281731 |
| 22 | -155829845193 |
| 23 | -2905151042481 |
| 24 | 8715453127443 |
[1,-2,-3,-1,3,3,-9,-17,51,155,-465,-2073,6219, 38227,-114681,-929569,2788707,28820619,-86461857, -1109652905,3328958715,51943281731,-155829845193, -2905151042481,8715453127443] |