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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 21 |
| 3 | -717 |
| 4 | 46025 |
| 5 | -4817209 |
| 6 | 734055069 |
| 7 | -154121194437 |
| 8 | 42674286160913 |
| 9 | -15062120873888497 |
| 10 | 6601538801733818277 |
| 11 | -3517682024725193957181 |
| 12 | 2239550167783452398617817 |
| 13 | -1678950113256157460626211113 |
[1,-1,21,-717,46025,-4817209,734055069, -154121194437,42674286160913,-15062120873888497, 6601538801733818277,-3517682024725193957181, 2239550167783452398617817, -1678950113256157460626211113] |