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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 15 |
| 4 | 256 |
| 5 | 7935 |
| 6 | 392526 |
| 7 | 28498246 |
| 8 | 2863702080 |
| 9 | 381411964485 |
| 10 | 65129544696250 |
| 11 | 13888321460879976 |
| 12 | 3620285828450155008 |
| 13 | 1133432920326577483795 |
| 14 | 419923892646668363653350 |
| 15 | 181795302703808044653240000 |
| 16 | 90971411268941227901619966976 |
[1,2,15,256,7935,392526,28498246,2863702080, 381411964485,65129544696250,13888321460879976, 3620285828450155008,1133432920326577483795, 419923892646668363653350, 181795302703808044653240000, 90971411268941227901619966976] |