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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 29 |
| 4 | 166 |
| 5 | 1424 |
| 6 | 8180 |
| 7 | 59259 |
| 8 | 373106 |
| 9 | 2412437 |
| 10 | 15444786 |
| 11 | 98319654 |
| 12 | 631317049 |
| 13 | 4000509800 |
| 14 | 25638291546 |
| 15 | 162726625613 |
| 16 | 1040425051956 |
| 17 | 6615457333531 |
| 18 | 42225119685838 |
| 19 | 268805885562269 |
| 20 | 1714155400353368 |
| 21 | 10919104048916128 |
[1,1,29,166,1424,8180,59259,373106,2412437, 15444786,98319654,631317049,4000509800, 25638291546,162726625613,1040425051956, 6615457333531,42225119685838,268805885562269, 1714155400353368,10919104048916128] |