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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 21 |
| 6 | 51 |
| 7 | 127 |
| 8 | 303 |
| 9 | 734 |
| 10 | 1751 |
| 11 | 4200 |
| 12 | 10004 |
| 13 | 23918 |
| 14 | 56981 |
| 15 | 135958 |
| 16 | 323996 |
| 17 | 772530 |
| 18 | 1840993 |
| 19 | 4388456 |
| 20 | 10458354 |
| 21 | 24926754 |
| 22 | 59405383 |
| 23 | 141581236 |
| 24 | 337417607 |
| 25 | 804153140 |
| 26 | 1916469872 |
| 27 | 4567399008 |
| 28 | 10885108498 |
| 29 | 25941679513 |
| 30 | 61824709789 |
[1,1,3,8,21,51,127,303,734,1751,4200,10004,23918, 56981,135958,323996,772530,1840993,4388456, 10458354,24926754,59405383,141581236,337417607, 804153140,1916469872,4567399008,10885108498, 25941679513,61824709789] |