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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | -12 |
| 5 | 60 |
| 6 | -450 |
| 7 | 2940 |
| 8 | -23408 |
| 9 | 179424 |
| 10 | -1610280 |
| 11 | 13910160 |
| 12 | -137455032 |
| 13 | 1245692448 |
| 14 | -12516311808 |
| 15 | 93103526880 |
| 16 | -527152105728 |
| 17 | -11362927602816 |
| 18 | 427180646000448 |
| 19 | -13403925787199616 |
| 20 | 328077695114329728 |
[1,0,0,0,-12,60,-450,2940,-23408,179424,-1610280, 13910160,-137455032,1245692448,-12516311808, 93103526880,-527152105728,-11362927602816, 427180646000448,-13403925787199616, 328077695114329728] |