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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | -3 |
| 4 | -15 |
| 5 | -3 |
| 6 | 297 |
| 7 | 1113 |
| 8 | -6783 |
| 9 | -77063 |
| 10 | 70609 |
| 11 | 5509845 |
| 12 | 18558705 |
| 13 | -430006731 |
| 14 | -4027228359 |
| 15 | 33282260529 |
| 16 | 727421677185 |
| 17 | -1454472663311 |
| 18 | -134584692783455 |
| 19 | -448480622503635 |
| 20 | 26232888936219249 |
| 21 | 254015086363619949 |
[1,1,1,-3,-15,-3,297,1113,-6783,-77063,70609, 5509845,18558705,-430006731,-4027228359, 33282260529,727421677185,-1454472663311, -134584692783455,-448480622503635, 26232888936219249,254015086363619949] |