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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 24 |
| 4 | -496 |
| 5 | 36000 |
| 6 | -3753408 |
| 7 | 556961664 |
| 8 | -111591202560 |
| 9 | 29054584410624 |
| 10 | -9541382573767680 |
| 11 | 3858875286730168320 |
| 12 | -1884995591107521540096 |
| 13 | 1094305223336273239449600 |
| 14 | -744771228363250138965196800 |
| 15 | 587358379156469629707528929280 |
[1,2,4,24,-496,36000,-3753408,556961664, -111591202560,29054584410624,-9541382573767680, 3858875286730168320,-1884995591107521540096, 1094305223336273239449600, -744771228363250138965196800, 587358379156469629707528929280] |