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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 24 |
| 6 | 116 |
| 7 | 636 |
| 8 | 3823 |
| 9 | 24729 |
| 10 | 170187 |
| 11 | 1236536 |
| 12 | 9431875 |
| 13 | 75202833 |
| 14 | 624669675 |
| 15 | 5390981898 |
| 16 | 48229922730 |
| 17 | 446459295023 |
| 18 | 4269397134669 |
| 19 | 42117578374712 |
| 20 | 428090022559608 |
| 21 | 4478159536973989 |
| 22 | 48163581285504612 |
| 23 | 532096844251876645 |
| 24 | 6033134642314812383 |
[1,1,2,6,24,116,636,3823,24729,170187,1236536, 9431875,75202833,624669675,5390981898,48229922730, 446459295023,4269397134669,42117578374712, 428090022559608,4478159536973989, 48163581285504612,532096844251876645, 6033134642314812383] |