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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | 5 |
| 2 | -25 |
| 3 | 119 |
| 4 | -565 |
| 5 | 2675 |
| 6 | -12661 |
| 7 | 59915 |
| 8 | -283525 |
| 9 | 1341659 |
| 10 | -6348805 |
| 11 | 30042875 |
| 12 | -142164421 |
| 13 | 672729275 |
| 14 | -3183389125 |
| 15 | 15063959099 |
| 16 | -71283419845 |
| 17 | 337316764475 |
| 18 | -1596200067781 |
| 19 | 7553299819835 |
| 20 | -35742598512325 |
| 21 | 169135792154939 |
| 22 | -800359161855685 |
| 23 | 3787340218204475 |
[-1,5,-25,119,-565,2675,-12661,59915,-283525, 1341659,-6348805,30042875,-142164421,672729275, -3183389125,15063959099,-71283419845,337316764475, -1596200067781,7553299819835,-35742598512325, 169135792154939,-800359161855685,3787340218204475] |