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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 3 |
| 6 | 4 |
| 7 | 10 |
| 8 | 37 |
| 9 | 366 |
| 10 | 13532 |
| 11 | 4952675 |
| 12 | 67019597734 |
| 13 | 331926286207224918 |
| 14 | 22245566178948766568816183137 |
| 15 | 7383888166355511098764350563784314022618210032 |
[0,1,2,2,3,4,10,37,366,13532,4952675,67019597734, 331926286207224918,22245566178948766568816183137, 7383888166355511098764350563784314022618210032] |