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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 8 |
| 4 | 32 |
| 5 | 84 |
| 6 | 346 |
| 7 | 1035 |
| 8 | 4398 |
| 9 | 14222 |
| 10 | 61684 |
| 11 | 210612 |
| 12 | 926902 |
| 13 | 3292765 |
| 14 | 14655294 |
| 15 | 53664171 |
| 16 | 240961436 |
| 17 | 903803156 |
| 18 | 4087224128 |
| 19 | 15633002424 |
| 20 | 71112783970 |
| 21 | 276447837298 |
| 22 | 1263743381144 |
| 23 | 4980630942098 |
| 24 | 22864035964645 |
| 25 | 91177566889046 |
| 26 | 420076191695644 |
| 27 | 1692376534197673 |
| 28 | 7821793195702664 |
[1,1,4,8,32,84,346,1035,4398,14222,61684,210612, 926902,3292765,14655294,53664171,240961436, 903803156,4087224128,15633002424,71112783970, 276447837298,1263743381144,4980630942098, 22864035964645,91177566889046,420076191695644, 1692376534197673,7821793195702664] |