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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 35 |
| 7 | 126 |
| 8 | 368 |
| 9 | 920 |
| 10 | 2285 |
| 11 | 5896 |
| 12 | 15456 |
| 13 | 41206 |
| 14 | 111892 |
| 15 | 304175 |
| 16 | 816621 |
| 17 | 2172175 |
| 18 | 5772781 |
| 19 | 15372397 |
| 20 | 41000988 |
| 21 | 109503212 |
| 22 | 292725922 |
| 23 | 782460503 |
| 24 | 2090016819 |
| 25 | 5579586307 |
| 26 | 14894046299 |
| 27 | 39762451293 |
| 28 | 106166731292 |
| 29 | 283495287002 |
[1,1,2,4,10,35,126,368,920,2285,5896,15456,41206, 111892,304175,816621,2172175,5772781,15372397, 41000988,109503212,292725922,782460503,2090016819, 5579586307,14894046299,39762451293,106166731292, 283495287002] |