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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 9 |
| 3 | 18 |
| 4 | -306 |
| 5 | -3240 |
| 6 | 49176 |
| 7 | 1466640 |
| 8 | -13626000 |
| 9 | -1172668032 |
| 10 | 75256704 |
| 11 | 1392243773184 |
| 12 | 18426692664576 |
| 13 | -2213592367094784 |
[0,9,18,-306,-3240,49176,1466640,-13626000, -1172668032,75256704,1392243773184,18426692664576, -2213592367094784] |