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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 3 |
| 3 | -13 |
| 4 | 73 |
| 5 | -521 |
| 6 | 4441 |
| 7 | -44185 |
| 8 | 502545 |
| 9 | -6429169 |
| 10 | 91393201 |
| 11 | -1429101521 |
| 12 | 24378097129 |
| 13 | -450504733849 |
| 14 | 8965682806809 |
| 15 | -191174795868841 |
| 16 | 4348171177591201 |
| 17 | -105077942935229537 |
| 18 | 2688685949077138657 |
| 19 | -72618903735812907553 |
| 20 | 2064598911185525708601 |
[1,-1,3,-13,73,-521,4441,-44185,502545,-6429169, 91393201,-1429101521,24378097129,-450504733849, 8965682806809,-191174795868841,4348171177591201, -105077942935229537,2688685949077138657, -72618903735812907553,2064598911185525708601] |