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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | -3 |
| 4 | 0 |
| 5 | 0 |
| 6 | 90 |
| 7 | -63 |
| 8 | 0 |
| 9 | -8880 |
| 10 | 22680 |
| 11 | -49203 |
| 12 | 2118600 |
| 13 | -12383280 |
| 14 | 60540480 |
| 15 | -1131841623 |
| 16 | 10857974400 |
| 17 | -87893114400 |
| 18 | 1246674306240 |
| 19 | -15590737021923 |
| 20 | 175749917616000 |
| 21 | -2471071936993440 |
| 22 | 35757593223327360 |
| 23 | -502589340005210703 |
| 24 | 7719667979121014400 |
[1,0,0,-3,0,0,90,-63,0,-8880,22680,-49203,2118600, -12383280,60540480,-1131841623,10857974400, -87893114400,1246674306240,-15590737021923, 175749917616000,-2471071936993440, 35757593223327360,-502589340005210703, 7719667979121014400] |