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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 4 |
| 3 | 56 |
| 4 | 1744 |
| 5 | 86208 |
| 6 | 6199744 |
| 7 | 608357504 |
| 8 | 77889982720 |
| 9 | 12588540708864 |
| 10 | 2503565961032704 |
| 11 | 600347512023062528 |
| 12 | 170721835772956659712 |
| 13 | 56780394898390577528832 |
| 14 | 21828678118361789793746944 |
[1,0,4,56,1744,86208,6199744,608357504, 77889982720,12588540708864,2503565961032704, 600347512023062528,170721835772956659712, 56780394898390577528832, 21828678118361789793746944] |