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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | -18 |
| 3 | 63 |
| 4 | -207 |
| 5 | 696 |
| 6 | -2415 |
| 7 | 8565 |
| 8 | -30714 |
| 9 | 110583 |
| 10 | -398439 |
| 11 | 1435152 |
| 12 | -5167083 |
| 13 | 18598065 |
| 14 | -66931314 |
| 15 | 240862563 |
| 16 | -866772819 |
| 17 | 3119198160 |
| 18 | -11224913079 |
| 19 | 40394716341 |
| 20 | -145367356794 |
| 21 | 523129840335 |
| 22 | -1882574375679 |
| 23 | 6774773362320 |
| 24 | -24380205972915 |
[1,3,-18,63,-207,696,-2415,8565,-30714,110583, -398439,1435152,-5167083,18598065,-66931314, 240862563,-866772819,3119198160,-11224913079, 40394716341,-145367356794,523129840335, -1882574375679,6774773362320,-24380205972915] |