| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | -4 |
| 4 | 0 |
| 5 | 16 |
| 6 | 108 |
| 7 | -64 |
| 8 | -864 |
| 9 | -2660 |
| 10 | -22464 |
| 11 | 33968 |
| 12 | 272268 |
| 13 | 1217152 |
| 14 | 4629312 |
| 15 | 68208188 |
| 16 | -98077824 |
| 17 | -1089798320 |
| 18 | -5246016084 |
| 19 | -32436365248 |
| 20 | -180561473568 |
| 21 | -3404617719332 |
| 22 | 5203858765248 |
| 23 | 55902314446832 |
| 24 | 354805454664396 |
| 25 | 2229923884913920 |
[1,1,0,-4,0,16,108,-64,-864,-2660,-22464,33968, 272268,1217152,4629312,68208188,-98077824, -1089798320,-5246016084,-32436365248, -180561473568,-3404617719332,5203858765248, 55902314446832,354805454664396,2229923884913920] |
