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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 8 |
| 8 | 23 |
| 9 | 64 |
| 10 | 222 |
| 11 | 752 |
| 12 | 2805 |
| 13 | 10475 |
| 14 | 40614 |
| 15 | 158994 |
| 16 | 633456 |
| 17 | 2548241 |
| 18 | 10362685 |
| 19 | 42485242 |
| 20 | 175557329 |
| 21 | 730314350 |
| 22 | 3056971164 |
| 23 | 12867007761 |
| 24 | 54434131848 |
| 25 | 231354091945 |
| 26 | 987496927875 |
| 27 | 4231561861914 |
| 28 | 18198894300129 |
| 29 | 78533356685275 |
| 30 | 339958801585826 |
[1,1,2,4,8,23,64,222,752,2805,10475,40614,158994, 633456,2548241,10362685,42485242,175557329, 730314350,3056971164,12867007761,54434131848, 231354091945,987496927875,4231561861914, 18198894300129,78533356685275,339958801585826] |