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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 20 |
| 7 | 47 |
| 8 | 129 |
| 9 | 427 |
| 10 | 1196 |
| 11 | 3482 |
| 12 | 10769 |
| 13 | 30174 |
| 14 | 86121 |
| 15 | 252178 |
| 16 | 694285 |
| 17 | 1923825 |
| 18 | 5380601 |
| 19 | 14505330 |
| 20 | 39099516 |
| 21 | 105522367 |
| 22 | 278190141 |
| 23 | 731086405 |
| 24 | 1916631823 |
| 25 | 4945238542 |
| 26 | 12702253352 |
| 27 | 32495656601 |
| 28 | 82177529409 |
| 29 | 206786628877 |
[1,1,2,3,5,20,47,129,427,1196,3482,10769,30174, 86121,252178,694285,1923825,5380601,14505330, 39099516,105522367,278190141,731086405,1916631823, 4945238542,12702253352,32495656601,82177529409, 206786628877] |