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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -3 |
| 2 | -15 |
| 3 | 21 |
| 4 | 1953 |
| 5 | 32461 |
| 6 | 77649 |
| 7 | -18557595 |
| 8 | -894805183 |
| 9 | -21405607651 |
| 10 | 421226202033 |
| 11 | 90171090228021 |
| 12 | 6418365899545825 |
| 13 | 230309031988304109 |
| 14 | -11126456208720437487 |
| 15 | -3093396343171182148731 |
| 16 | -342554566975833968005503 |
[1,-3,-15,21,1953,32461,77649,-18557595, -894805183,-21405607651,421226202033, 90171090228021,6418365899545825, 230309031988304109,-11126456208720437487, -3093396343171182148731,-342554566975833968005503] |