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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 7 |
| 3 | -75 |
| 4 | 1089 |
| 5 | -20025 |
| 6 | 446535 |
| 7 | -11715795 |
| 8 | 353743425 |
| 9 | -12084751665 |
| 10 | 460905128775 |
| 11 | -19414191656475 |
| 12 | 895154327661825 |
| 13 | -44844879530075625 |
| 14 | 2425592881954016775 |
| 15 | -140881250370301315875 |
| 16 | 8745197742014671562625 |
| 17 | -577792180264444615094625 |
| 18 | 40483044280613870034474375 |
[1,-1,7,-75,1089,-20025,446535,-11715795, 353743425,-12084751665,460905128775, -19414191656475,895154327661825, -44844879530075625,2425592881954016775, -140881250370301315875,8745197742014671562625, -577792180264444615094625, 40483044280613870034474375] |