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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | -12 |
| 5 | 60 |
| 6 | -330 |
| 7 | 2100 |
| 8 | -13664 |
| 9 | 96768 |
| 10 | -747720 |
| 11 | 6233040 |
| 12 | -55757592 |
| 13 | 529420320 |
| 14 | -5249506080 |
| 15 | 53003714400 |
| 16 | -519287424000 |
| 17 | 4336798757760 |
| 18 | -12704182464960 |
| 19 | -768063270038400 |
| 20 | 31846322269825920 |
| 21 | -952431265450344960 |
[1,0,0,0,-12,60,-330,2100,-13664,96768,-747720, 6233040,-55757592,529420320,-5249506080, 53003714400,-519287424000,4336798757760, -12704182464960,-768063270038400, 31846322269825920,-952431265450344960] |