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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 24 |
| 3 | 720 |
| 4 | 24024 |
| 5 | 570050 |
| 6 | 12702057 |
| 7 | 298167456 |
| 8 | 7208117568 |
| 9 | 173161739904 |
| 10 | 4127570837184 |
| 11 | 98339773309856 |
| 12 | 2347000930925753 |
| 13 | 56041331020681154 |
| 14 | 1337774984135116376 |
| 15 | 31928671287098350544 |
| 16 | 762059700266910857880 |
[2,24,720,24024,570050,12702057,298167456, 7208117568,173161739904,4127570837184, 98339773309856,2347000930925753,56041331020681154, 1337774984135116376,31928671287098350544, 762059700266910857880] |