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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 3 |
| 4 | -8 |
| 5 | 25 |
| 6 | -99 |
| 7 | 721 |
| 8 | -5704 |
| 9 | 40881 |
| 10 | -340325 |
| 11 | 3628801 |
| 12 | -41245511 |
| 13 | 479001601 |
| 14 | -6129725315 |
| 15 | 87212177053 |
| 16 | -1317906346184 |
| 17 | 20922789888001 |
| 18 | -354320889234597 |
| 19 | 6402373705728001 |
| 20 | -121882630320799633 |
| 21 | 2432928081076384321 |
| 22 | -51041048673495232715 |
[1,0,3,-8,25,-99,721,-5704,40881,-340325,3628801, -41245511,479001601,-6129725315,87212177053, -1317906346184,20922789888001,-354320889234597, 6402373705728001,-121882630320799633, 2432928081076384321,-51041048673495232715] |