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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 5 |
| 4 | -13 |
| 5 | 75 |
| 6 | -465 |
| 7 | 3509 |
| 8 | -29492 |
| 9 | 276310 |
| 10 | -2854776 |
| 11 | 32242512 |
| 12 | -395295109 |
| 13 | 5230184477 |
| 14 | -74303722489 |
| 15 | 1128399929626 |
| 16 | -18245417102767 |
| 17 | 313000130900207 |
| 18 | -5678742973964699 |
| 19 | 108649510570970878 |
| 20 | -2186444702147475131 |
| 21 | 46169315317847827548 |
[1,1,0,5,-13,75,-465,3509,-29492,276310,-2854776, 32242512,-395295109,5230184477,-74303722489, 1128399929626,-18245417102767,313000130900207, -5678742973964699,108649510570970878, -2186444702147475131,46169315317847827548] |