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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | -144 |
| 4 | -2568 |
| 5 | -28200 |
| 6 | 0 |
| 7 | 15203328 |
| 8 | 675195936 |
| 9 | 16696909080 |
| 10 | 0 |
| 11 | -25789252433472 |
| 12 | -1612260342054360 |
| 13 | -54804262577596532 |
| 14 | 0 |
| 15 | 161017938434267136000 |
| 16 | 13718166932451951573120 |
| 17 | 621130358284578576358416 |
| 18 | 0 |
| 19 | -3008072527724272784969384000 |
| 20 | -320196271193421334219630013080 |
[1,0,-144,-2568,-28200,0,15203328,675195936, 16696909080,0,-25789252433472,-1612260342054360, -54804262577596532,0,161017938434267136000, 13718166932451951573120,621130358284578576358416, 0,-3008072527724272784969384000, -320196271193421334219630013080] |