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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -3 |
| 2 | 3 |
| 3 | -9 |
| 4 | 15 |
| 5 | -45 |
| 6 | 45 |
| 7 | -135 |
| 8 | 255 |
| 9 | -765 |
| 10 | 765 |
| 11 | -2295 |
| 12 | 3825 |
| 13 | -11475 |
| 14 | 11475 |
| 15 | -34425 |
| 16 | 65535 |
| 17 | -196605 |
| 18 | 196605 |
| 19 | -589815 |
| 20 | 983025 |
| 21 | -2949075 |
| 22 | 2949075 |
| 23 | -8847225 |
| 24 | 16711425 |
| 25 | -50134275 |
| 26 | 50134275 |
| 27 | -150402825 |
| 28 | 250671375 |
| 29 | -752014125 |
| 30 | 752014125 |
[1,-3,3,-9,15,-45,45,-135,255,-765,765,-2295,3825, -11475,11475,-34425,65535,-196605,196605,-589815, 983025,-2949075,2949075,-8847225,16711425, -50134275,50134275,-150402825,250671375, -752014125,752014125] |