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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 37824 |
| 9 | 317352 |
| 10 | 2904864 |
| 11 | 28985856 |
| 12 | 318625344 |
| 13 | 3752068876 |
| 14 | 47528807384 |
| 15 | 637960792172 |
| 16 | 9188691694700 |
[1,2,6,24,120,720,5040,37824,317352,2904864, 28985856,318625344,3752068876,47528807384, 637960792172,9188691694700] |