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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 140 |
| 4 | 5394 |
| 5 | 336024 |
| 6 | 30663840 |
| 7 | 3846629520 |
| 8 | 634415055120 |
| 9 | 133073632016640 |
| 10 | 34596321663980160 |
| 11 | 10919217470376902400 |
| 12 | 4113179201266142515200 |
| 13 | 1822997615295693513600000 |
| 14 | 939158618068666181592806400 |
| 15 | 556530141861219809204393472000 |
[1,7,140,5394,336024,30663840,3846629520, 634415055120,133073632016640,34596321663980160, 10919217470376902400,4113179201266142515200, 1822997615295693513600000, 939158618068666181592806400, 556530141861219809204393472000] |