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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -2 |
| 3 | -3 |
| 4 | 16 |
| 5 | 90 |
| 6 | -204 |
| 7 | -4200 |
| 8 | -5312 |
| 9 | 254016 |
| 10 | 1586160 |
| 11 | -17970480 |
| 12 | -294932736 |
| 13 | 790115040 |
| 14 | 54224747136 |
| 15 | 216483714720 |
| 16 | -10481294822400 |
| 17 | -137535688281600 |
| 18 | 1798183916660736 |
| 19 | 58769251106526720 |
| 20 | -95282580797291520 |
| 21 | -23811620975395061760 |
| 22 | -203282679617698222080 |
[1,0,-2,-3,16,90,-204,-4200,-5312,254016,1586160, -17970480,-294932736,790115040,54224747136, 216483714720,-10481294822400,-137535688281600, 1798183916660736,58769251106526720, -95282580797291520,-23811620975395061760, -203282679617698222080] |