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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 40 |
| 6 | 166 |
| 7 | 749 |
| 8 | 3683 |
| 9 | 19275 |
| 10 | 107806 |
| 11 | 640970 |
| 12 | 4024912 |
| 13 | 26653653 |
| 14 | 185401581 |
| 15 | 1350624721 |
| 16 | 10282222002 |
| 17 | 81592209580 |
| 18 | 673535269054 |
| 19 | 5773214891137 |
| 20 | 51291776763863 |
| 21 | 471617190143567 |
| 22 | 4481375500319334 |
| 23 | 43947651280912186 |
| 24 | 444258975094335440 |
[0,1,3,10,40,166,749,3683,19275,107806,640970, 4024912,26653653,185401581,1350624721,10282222002, 81592209580,673535269054,5773214891137, 51291776763863,471617190143567,4481375500319334, 43947651280912186,444258975094335440] |