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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 29 |
| 6 | 75 |
| 7 | 203 |
| 8 | 557 |
| 9 | 1561 |
| 10 | 4427 |
| 11 | 12706 |
| 12 | 36819 |
| 13 | 107576 |
| 14 | 316579 |
| 15 | 937471 |
| 16 | 2791487 |
| 17 | 8352973 |
| 18 | 25104573 |
| 19 | 75749240 |
| 20 | 229379444 |
| 21 | 696851166 |
| 22 | 2123304184 |
| 23 | 6487295518 |
| 24 | 19870096689 |
| 25 | 61001089214 |
| 26 | 187673207413 |
| 27 | 578532522637 |
| 28 | 1786712575547 |
[1,1,2,5,11,29,75,203,557,1561,4427,12706,36819, 107576,316579,937471,2791487,8352973,25104573, 75749240,229379444,696851166,2123304184, 6487295518,19870096689,61001089214,187673207413, 578532522637,1786712575547] |