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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -1 |
| 3 | 3 |
| 4 | -22 |
| 5 | 100 |
| 6 | -580 |
| 7 | 3150 |
| 8 | -16868 |
| 9 | 80568 |
| 10 | -141500 |
| 11 | -4254580 |
| 12 | 105666112 |
| 13 | -1880236800 |
| 14 | 31074394312 |
| 15 | -508890083520 |
| 16 | 8476622031888 |
| 17 | -145412857677888 |
| 18 | 2584745973422384 |
| 19 | -47756915743199760 |
| 20 | 918437313488897760 |
[1,0,-1,3,-22,100,-580,3150,-16868,80568,-141500, -4254580,105666112,-1880236800,31074394312, -508890083520,8476622031888,-145412857677888, 2584745973422384,-47756915743199760, 918437313488897760] |