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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -1 |
| 3 | 3 |
| 4 | -8 |
| 5 | 20 |
| 6 | -34 |
| 7 | -126 |
| 8 | 2514 |
| 9 | -28008 |
| 10 | 285774 |
| 11 | -2922810 |
| 12 | 30858048 |
| 13 | -339954264 |
| 14 | 3920819748 |
| 15 | -47319853140 |
| 16 | 596005041852 |
| 17 | -7799132781792 |
| 18 | 105344546511684 |
| 19 | -1454910026870412 |
| 20 | 20242465245436128 |
| 21 | -276289562032117200 |
| 22 | 3490199850169557480 |
[1,0,-1,3,-8,20,-34,-126,2514,-28008,285774, -2922810,30858048,-339954264,3920819748, -47319853140,596005041852,-7799132781792, 105344546511684,-1454910026870412, 20242465245436128,-276289562032117200, 3490199850169557480] |