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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 40 |
| 4 | 800 |
| 5 | 33432 |
| 6 | 2888696 |
| 7 | 517902680 |
| 8 | 192533704008 |
| 9 | 148429379845856 |
| 10 | 237284500891487840 |
| 11 | 786611979025079107456 |
| 12 | 5407447771030956200932952 |
| 13 | 77084070831919712319047890192 |
| 14 | 2278648745820732735808198902023640 |
[1,4,40,800,33432,2888696,517902680,192533704008, 148429379845856,237284500891487840, 786611979025079107456,5407447771030956200932952, 77084070831919712319047890192, 2278648745820732735808198902023640] |