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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 4 |
| 3 | -6 |
| 4 | 43 |
| 5 | -170 |
| 6 | 1300 |
| 7 | -8085 |
| 8 | 74365 |
| 9 | -622260 |
| 10 | 6828550 |
| 11 | -71435375 |
| 12 | 916947475 |
| 13 | -11485611150 |
| 14 | 169312686400 |
| 15 | -2467472314125 |
| 16 | 41136075813625 |
| 17 | -683273434337000 |
| 18 | 12720608899482250 |
| 19 | -237102839757034875 |
[1,0,4,-6,43,-170,1300,-8085,74365,-622260, 6828550,-71435375,916947475,-11485611150, 169312686400,-2467472314125,41136075813625, -683273434337000,12720608899482250, -237102839757034875] |