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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 43 |
| 6 | 143 |
| 7 | 506 |
| 8 | 1870 |
| 9 | 7107 |
| 10 | 27474 |
| 11 | 107274 |
| 12 | 421268 |
| 13 | 1659725 |
| 14 | 6551041 |
| 15 | 25884007 |
| 16 | 102330007 |
| 17 | 404682554 |
| 18 | 1600678795 |
| 19 | 6331951858 |
| 20 | 25049290301 |
| 21 | 99098453901 |
| 22 | 392054049162 |
| 23 | 1551062360070 |
| 24 | 6136418173129 |
| 25 | 24277388110318 |
[1,1,2,5,14,43,143,506,1870,7107,27474,107274, 421268,1659725,6551041,25884007,102330007, 404682554,1600678795,6331951858,25049290301, 99098453901,392054049162,1551062360070, 6136418173129,24277388110318] |