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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 0 |
| 3 | 40 |
| 4 | 800 |
| 5 | 20288 |
| 6 | 606400 |
| 7 | 20971904 |
| 8 | 825910528 |
| 9 | 36572366848 |
| 10 | 1802071653376 |
| 11 | 97938520514560 |
| 12 | 5826195568779264 |
| 13 | 376854594173526016 |
| 14 | 26349673341110894592 |
| 15 | 1981251753509044977664 |
| 16 | 159466640566146568814592 |
| 17 | 13683137506507195162427392 |
[2,0,40,800,20288,606400,20971904,825910528, 36572366848,1802071653376,97938520514560, 5826195568779264,376854594173526016, 26349673341110894592,1981251753509044977664, 159466640566146568814592, 13683137506507195162427392] |