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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | -1 |
| 3 | -7 |
| 4 | 18 |
| 5 | 243 |
| 6 | -1785 |
| 7 | -19086 |
| 8 | 308980 |
| 9 | 2736225 |
| 10 | -90239805 |
| 11 | -495769586 |
| 12 | 38522052690 |
| 13 | 39766893593 |
| 14 | -22481798964989 |
| 15 | 111035038388104 |
| 16 | 16941789968380680 |
| 17 | -219516343596465735 |
| 18 | -15750892172912678361 |
[0,2,-1,-7,18,243,-1785,-19086,308980,2736225, -90239805,-495769586,38522052690,39766893593, -22481798964989,111035038388104,16941789968380680, -219516343596465735,-15750892172912678361] |