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| n | a(n) |
|---|---|
| 1 | -1 |
| 2 | 2 |
| 3 | -6 |
| 4 | 36 |
| 5 | -300 |
| 6 | 3270 |
| 7 | -43680 |
| 8 | 691992 |
| 9 | -12670560 |
| 10 | 263281050 |
| 11 | -6119720640 |
| 12 | 157325242140 |
| 13 | -4431909081600 |
| 14 | 135757694361198 |
| 15 | -4492575720622080 |
| 16 | 159723265791222000 |
| 17 | -6071451523596103680 |
| 18 | 245720759937001346610 |
| 19 | -10548874580411105832960 |
| 20 | 478801529559871868317140 |
| 21 | -22909292930454154076160000 |
| 22 | 1152457216135660417348971990 |
| 23 | -60807227650606789798265487360 |
| 24 | 3357825559218695417748978547080 |
[-1,2,-6,36,-300,3270,-43680,691992,-12670560, 263281050,-6119720640,157325242140,-4431909081600, 135757694361198,-4492575720622080, 159723265791222000,-6071451523596103680, 245720759937001346610,-10548874580411105832960, 478801529559871868317140, -22909292930454154076160000, 1152457216135660417348971990, -60807227650606789798265487360, 3357825559218695417748978547080] |