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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 40 |
| 5 | 341 |
| 6 | 3936 |
| 7 | 57107 |
| 8 | 992384 |
| 9 | 20025385 |
| 10 | 459466240 |
| 11 | 11804134079 |
| 12 | 335571265536 |
| 13 | 10456512176189 |
| 14 | 354362575314944 |
| 15 | 12975301760361163 |
| 16 | 510462668072058880 |
| 17 | 21472710312090391889 |
| 18 | 961728814178702327808 |
| 19 | 45692671937666739799799 |
| 20 | 2295278998002033651875840 |
| 21 | 121545436687537993689631525 |
| 22 | 6767130413049423041105231872 |
| 23 | 395177438856180565803457658627 |
| 24 | 24152146710231984411570685870080 |
[1,2,7,40,341,3936,57107,992384,20025385, 459466240,11804134079,335571265536,10456512176189, 354362575314944,12975301760361163, 510462668072058880,21472710312090391889, 961728814178702327808,45692671937666739799799, 2295278998002033651875840, 121545436687537993689631525, 6767130413049423041105231872, 395177438856180565803457658627, 24152146710231984411570685870080] |