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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | -1 |
| 4 | 2 |
| 5 | 6 |
| 6 | -11 |
| 7 | -35 |
| 8 | 73 |
| 9 | 232 |
| 10 | -516 |
| 11 | -1646 |
| 12 | 3825 |
| 13 | 12239 |
| 14 | -29344 |
| 15 | -94137 |
| 16 | 231050 |
| 17 | 742825 |
| 18 | -1856679 |
| 19 | -5980056 |
| 20 | 15166101 |
| 21 | 48922556 |
| 22 | -125557710 |
| 23 | -405553786 |
| 24 | 1051197507 |
| 25 | 3399234751 |
[1,1,0,-1,2,6,-11,-35,73,232,-516,-1646,3825, 12239,-29344,-94137,231050,742825,-1856679, -5980056,15166101,48922556,-125557710,-405553786, 1051197507,3399234751] |