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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | -6 |
| 2 | 18 |
| 3 | -60 |
| 4 | 210 |
| 5 | -756 |
| 6 | 2772 |
| 7 | -10296 |
| 8 | 38610 |
| 9 | -145860 |
| 10 | 554268 |
| 11 | -2116296 |
| 12 | 8112462 |
| 13 | -31201644 |
| 14 | 120347532 |
| 15 | -465328200 |
| 16 | 1803025410 |
| 17 | -6999149124 |
| 18 | 27213719148 |
| 19 | -105960069864 |
| 20 | 413078158350 |
| 21 | -1612098272460 |
| 22 | 6297409350492 |
| 23 | -24620247483624 |
| 24 | 96324799842498 |
| 25 | -377102656201956 |
| 26 | 1477141800784668 |
[3,-6,18,-60,210,-756,2772,-10296,38610,-145860, 554268,-2116296,8112462,-31201644,120347532, -465328200,1803025410,-6999149124,27213719148, -105960069864,413078158350,-1612098272460, 6297409350492,-24620247483624,96324799842498, -377102656201956,1477141800784668] |