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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 8 |
| 3 | 165 |
| 4 | 6384 |
| 5 | 397320 |
| 6 | 36273600 |
| 7 | 4566166605 |
| 8 | 757975618400 |
| 9 | 160424015864112 |
| 10 | 42164387189608320 |
| 11 | 13473505313334666600 |
| 12 | 5144136790654611953280 |
| 13 | 2312696796696904699224000 |
| 14 | 1209297981696245764641077760 |
| 15 | 727688337054213932985609546525 |
[1,1,8,165,6384,397320,36273600,4566166605, 757975618400,160424015864112,42164387189608320, 13473505313334666600,5144136790654611953280, 2312696796696904699224000, 1209297981696245764641077760, 727688337054213932985609546525] |