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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | -1 |
| 2 | 15 |
| 3 | -610 |
| 4 | 27951 |
| 5 | -1308385 |
| 6 | 61433856 |
| 7 | -2885861665 |
| 8 | 135572548335 |
| 9 | -6369013518946 |
| 10 | 299207991620175 |
| 11 | -14056406104466881 |
| 12 | 660351875572408320 |
| 13 | -31022481722865482305 |
| 14 | 1457396288941918481871 |
| 15 | -68466603097469928960610 |
[0,-1,15,-610,27951,-1308385,61433856,-2885861665, 135572548335,-6369013518946,299207991620175, -14056406104466881,660351875572408320, -31022481722865482305,1457396288941918481871, -68466603097469928960610] |