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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | 9 |
| 4 | -18 |
| 5 | 44 |
| 6 | -54 |
| 7 | 350 |
| 8 | -1359 |
| 9 | 3789 |
| 10 | -9585 |
| 11 | 42489 |
| 12 | -163900 |
| 13 | 543474 |
| 14 | -1933092 |
| 15 | 7499404 |
| 16 | -27668718 |
| 17 | 100329714 |
| 18 | -371138346 |
| 19 | 1394575578 |
| 20 | -5236658316 |
| 21 | 19587163968 |
| 22 | -73536845444 |
| 23 | 278088068628 |
| 24 | -1052804678958 |
| 25 | 3985553554074 |
| 26 | -15132118280498 |
| 27 | 57617112474306 |
| 28 | -219680808219216 |
[1,1,-1,9,-18,44,-54,350,-1359,3789,-9585,42489, -163900,543474,-1933092,7499404,-27668718, 100329714,-371138346,1394575578,-5236658316, 19587163968,-73536845444,278088068628, -1052804678958,3985553554074,-15132118280498, 57617112474306,-219680808219216] |