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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 10 |
| 5 | 42 |
| 6 | 146 |
| 7 | 314 |
| 8 | 1806 |
| 9 | 23226 |
| 10 | 42814 |
| 11 | 141578 |
| 12 | 395002 |
| 13 | 3263442 |
| 14 | 542731938 |
| 15 | 2372530250 |
| 16 | 21123367578 |
| 17 | 41921883010 |
| 18 | 216160029242 |
| 19 | 780133887002 |
| 20 | 10650056950806 |
| 21 | 294568607121655146 |
| 22 | 5923457746066090230 |
| 23 | 11257799577242104090 |
| 24 | 446785773769478686986 |
| 25 | 2209269832769594087610 |
[1,2,6,10,42,146,314,1806,23226,42814,141578, 395002,3263442,542731938,2372530250,21123367578, 41921883010,216160029242,780133887002, 10650056950806,294568607121655146, 5923457746066090230,11257799577242104090, 446785773769478686986,2209269832769594087610] |