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| n | a(n) |
|---|---|
| 2 | 0 |
| 3 | 0 |
| 4 | -72 |
| 5 | 0 |
| 6 | 9600 |
| 7 | 0 |
| 8 | 23970816 |
| 9 | 0 |
| 10 | 0 |
| 11 | -8814759178752000000 |
| 12 | -1217765613534782800527360 |
| 13 | 0 |
| 14 | 2555625991208076641833058304 |
| 15 | 0 |
| 16 | 0 |
| 17 | 0 |
| 18 | 164525463228624478317575381527120287356682240 |
| 19 | -33094833021317386202938131485140597289779200 |
| 20 | 0 |
[0,0,-72,0,9600,0,23970816,0,0, -8814759178752000000,-1217765613534782800527360,0, 2555625991208076641833058304,0,0,0, 164525463228624478317575381527120287356682240, -33094833021317386202938131485140597289779200,0] |