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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -1 |
| 3 | 6 |
| 4 | 0 |
| 5 | -96 |
| 6 | 1856 |
| 7 | -19866 |
| 8 | 194701 |
| 9 | -143840 |
| 10 | -12421376 |
| 11 | -2242688 |
| 12 | 7161224400 |
| 13 | -182262318208 |
| 14 | 4419601227184 |
| 15 | -105598371081024 |
| 16 | 1963290383833664 |
| 17 | -34552138617760368 |
| 18 | 6240219707831587 |
| 19 | 4597964531722783442 |
| 20 | 255030441797039438464 |
| 21 | -20656928385327220865224 |
[1,0,-1,6,0,-96,1856,-19866,194701,-143840, -12421376,-2242688,7161224400,-182262318208, 4419601227184,-105598371081024,1963290383833664, -34552138617760368,6240219707831587, 4597964531722783442,255030441797039438464, -20656928385327220865224] |