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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -5 |
| 2 | 5 |
| 3 | 30 |
| 4 | 180 |
| 5 | 1410 |
| 6 | 14790 |
| 7 | 203880 |
| 8 | 3559560 |
| 9 | 75659760 |
| 10 | 1893764160 |
| 11 | 54430097760 |
| 12 | 1763357958000 |
| 13 | 63501756552720 |
| 14 | 2514747808468080 |
| 15 | 108572621062573440 |
| 16 | 5074353268651935360 |
| 17 | 255201626973301102080 |
| 18 | 13740802156877800538880 |
| 19 | 788580746923723472839680 |
[1,-5,5,30,180,1410,14790,203880,3559560,75659760, 1893764160,54430097760,1763357958000, 63501756552720,2514747808468080, 108572621062573440,5074353268651935360, 255201626973301102080,13740802156877800538880, 788580746923723472839680] |