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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -4 |
| 2 | 72 |
| 3 | -2400 |
| 4 | 117600 |
| 5 | -7620480 |
| 6 | 614718720 |
| 7 | -59364264960 |
| 8 | 6678479808000 |
| 9 | -857813628672000 |
| 10 | 123868287980236800 |
| 11 | -19863969090648883200 |
| 12 | 3502679882984419737600 |
| 13 | -673592285189311488000000 |
| 14 | 140299650258002307072000000 |
| 15 | -31464534897861317399347200000 |
[1,-4,72,-2400,117600,-7620480,614718720, -59364264960,6678479808000,-857813628672000, 123868287980236800,-19863969090648883200, 3502679882984419737600,-673592285189311488000000, 140299650258002307072000000, -31464534897861317399347200000] |