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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 18 |
| 7 | 41 |
| 8 | 102 |
| 9 | 252 |
| 10 | 666 |
| 11 | 1789 |
| 12 | 5031 |
| 13 | 14486 |
| 14 | 43280 |
| 15 | 132777 |
| 16 | 420267 |
| 17 | 1366307 |
| 18 | 4566966 |
| 19 | 15661086 |
| 20 | 55081118 |
| 21 | 198425478 |
| 22 | 731661754 |
| 23 | 2758808581 |
| 24 | 10629386376 |
| 25 | 41814350148 |
| 26 | 167830018952 |
| 27 | 686822393793 |
| 28 | 2864024856054 |
| 29 | 12162059027416 |
| 30 | 52564545391789 |
[1,1,2,4,8,18,41,102,252,666,1789,5031,14486, 43280,132777,420267,1366307,4566966,15661086, 55081118,198425478,731661754,2758808581, 10629386376,41814350148,167830018952,686822393793, 2864024856054,12162059027416,52564545391789] |