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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 50 |
| 5 | 285 |
| 6 | 1696 |
| 7 | 10647 |
| 8 | 68842 |
| 9 | 456922 |
| 10 | 3091546 |
| 11 | 21252396 |
| 12 | 147992264 |
| 13 | 1041779912 |
| 14 | 7401119718 |
| 15 | 52996414666 |
| 16 | 382095695324 |
| 17 | 2771458821772 |
| 18 | 20209364313202 |
| 19 | 148064910503435 |
| 20 | 1089415620952020 |
| 21 | 8046283404651000 |
| 22 | 59635009544475814 |
| 23 | 443380411766040664 |
[1,2,10,50,285,1696,10647,68842,456922,3091546, 21252396,147992264,1041779912,7401119718, 52996414666,382095695324,2771458821772, 20209364313202,148064910503435,1089415620952020, 8046283404651000,59635009544475814, 443380411766040664] |