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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 24 |
| 4 | 720 |
| 5 | 2520 |
| 6 | 120960 |
| 7 | 259459200 |
| 8 | 1357171200 |
| 9 | 4929724800 |
| 10 | 42608389824000 |
| 11 | 11912739135897600 |
| 12 | 59907396092544000 |
| 13 | 20458385028297216000 |
| 14 | 7926428532945162240000 |
| 15 | 4693751193479184764928000 |
| 16 | 328774885640356760904499200000 |
| 17 | 12797917159224592605450240000 |
[1,1,24,720,2520,120960,259459200,1357171200, 4929724800,42608389824000,11912739135897600, 59907396092544000,20458385028297216000, 7926428532945162240000,4693751193479184764928000, 328774885640356760904499200000, 12797917159224592605450240000] |