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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 14 |
| 4 | 48 |
| 5 | 162 |
| 6 | 556 |
| 7 | 1934 |
| 8 | 6784 |
| 9 | 23954 |
| 10 | 85044 |
| 11 | 303294 |
| 12 | 1085712 |
| 13 | 3898962 |
| 14 | 14040156 |
| 15 | 50678814 |
| 16 | 183309312 |
| 17 | 664263714 |
| 18 | 2411050084 |
| 19 | 8764098158 |
| 20 | 31899231088 |
| 21 | 116244082178 |
| 22 | 424064770188 |
| 23 | 1548543412398 |
| 24 | 5659898710912 |
[1,2,4,14,48,162,556,1934,6784,23954,85044,303294, 1085712,3898962,14040156,50678814,183309312, 664263714,2411050084,8764098158,31899231088, 116244082178,424064770188,1548543412398, 5659898710912] |