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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -20 |
| 3 | -560 |
| 4 | -7920 |
| 5 | 1034880 |
| 6 | 172569280 |
| 7 | 12339608320 |
| 8 | -1902800305920 |
| 9 | -1037015219466240 |
| 10 | -208832669083243520 |
| 11 | 24402030281141555200 |
| 12 | 43057075784745711636480 |
| 13 | 18939654540025835056496640 |
[1,0,-20,-560,-7920,1034880,172569280,12339608320, -1902800305920,-1037015219466240, -208832669083243520,24402030281141555200, 43057075784745711636480, 18939654540025835056496640] |