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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 125 |
| 6 | 1055 |
| 7 | 11754 |
| 8 | 187498 |
| 9 | 4372206 |
| 10 | 142427556 |
| 11 | 6649078485 |
| 12 | 443418423639 |
| 13 | 42015106781746 |
| 14 | 5681500677861845 |
| 15 | 1094937801983952063 |
| 16 | 300642401916076713227 |
| 17 | 117675702292067958725570 |
[1,2,6,24,125,1055,11754,187498,4372206,142427556, 6649078485,443418423639,42015106781746, 5681500677861845,1094937801983952063, 300642401916076713227,117675702292067958725570] |