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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -2 |
| 3 | -9 |
| 4 | -40 |
| 5 | -205 |
| 6 | -1236 |
| 7 | -8659 |
| 8 | -69280 |
| 9 | -623529 |
| 10 | -6235300 |
| 11 | -68588311 |
| 12 | -823059744 |
| 13 | -10699776685 |
| 14 | -149796873604 |
| 15 | -2246953104075 |
| 16 | -35951249665216 |
| 17 | -611171244308689 |
| 18 | -11001082397556420 |
| 19 | -209020565553571999 |
[1,0,-2,-9,-40,-205,-1236,-8659,-69280,-623529, -6235300,-68588311,-823059744,-10699776685, -149796873604,-2246953104075,-35951249665216, -611171244308689,-11001082397556420, -209020565553571999] |