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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 24 |
| 5 | 78 |
| 6 | 313 |
| 7 | 1557 |
| 8 | 9606 |
| 9 | 73482 |
| 10 | 696736 |
| 11 | 8187149 |
| 12 | 119214337 |
| 13 | 2150935400 |
| 14 | 48085463503 |
| 15 | 1331903411529 |
| 16 | 45708405952786 |
| 17 | 1943464419169294 |
| 18 | 102378212255343442 |
| 19 | 6681679619583450775 |
| 20 | 540264005909352759970 |
| 21 | 54120992439329583459008 |
| 22 | 6716802027097934788929023 |
[1,2,4,9,24,78,313,1557,9606,73482,696736,8187149, 119214337,2150935400,48085463503,1331903411529, 45708405952786,1943464419169294, 102378212255343442,6681679619583450775, 540264005909352759970,54120992439329583459008, 6716802027097934788929023] |