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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 252 |
| 3 | 756756 |
| 4 | 11732745024 |
| 5 | 623360743125120 |
| 6 | 88832646059788350720 |
| 7 | 28837919555681211870935040 |
| 8 | 18975581770994682860770223800320 |
| 9 | 23183587808948692737291767860055162880 |
| 10 | 49120458506088132224064306071170476903628800 |
[1,1,252,756756,11732745024,623360743125120, 88832646059788350720,28837919555681211870935040, 18975581770994682860770223800320, 23183587808948692737291767860055162880, 49120458506088132224064306071170476903628800] |