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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 162 |
| 5 | 3888 |
| 6 | 144768 |
| 7 | 7693920 |
| 8 | 551981520 |
| 9 | 51355426992 |
| 10 | 6010929609408 |
| 11 | 864202875949440 |
| 12 | 149698423474606080 |
| 13 | 30747550680449611200 |
| 14 | 7388611598645058636000 |
| 15 | 2053517715502048081023360 |
| 16 | 653614372412684344833419520 |
| 17 | 236202930442590804658824312960 |
[1,1,2,12,162,3888,144768,7693920,551981520, 51355426992,6010929609408,864202875949440, 149698423474606080,30747550680449611200, 7388611598645058636000,2053517715502048081023360, 653614372412684344833419520, 236202930442590804658824312960] |