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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 1 |
| 3 | 0 |
| 4 | -2 |
| 5 | 12 |
| 6 | -16 |
| 7 | 144 |
| 8 | 368 |
| 9 | 4768 |
| 10 | 39488 |
| 11 | 412288 |
| 12 | 4577280 |
| 13 | 55671808 |
| 14 | 731390976 |
| 15 | 10335518720 |
| 16 | 156303439872 |
| 17 | 2518984822784 |
| 18 | 43099089166336 |
| 19 | 780268880543744 |
| 20 | 14902336357040128 |
| 21 | 299452809649520640 |
| 22 | 6315501510334480384 |
| 23 | 139485953831272710144 |
| 24 | 3219718099932104622080 |
[1,-1,1,0,-2,12,-16,144,368,4768,39488,412288, 4577280,55671808,731390976,10335518720, 156303439872,2518984822784,43099089166336, 780268880543744,14902336357040128, 299452809649520640,6315501510334480384, 139485953831272710144,3219718099932104622080] |