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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 14 |
| 6 | 39 |
| 7 | 114 |
| 8 | 339 |
| 9 | 1028 |
| 10 | 3163 |
| 11 | 9852 |
| 12 | 31005 |
| 13 | 98436 |
| 14 | 314901 |
| 15 | 1014070 |
| 16 | 3284657 |
| 17 | 10694314 |
| 18 | 34979667 |
| 19 | 114887846 |
| 20 | 378750951 |
| 21 | 1252865288 |
| 22 | 4157150327 |
| 23 | 13832926200 |
| 24 | 46148704121 |
| 25 | 154327715592 |
| 26 | 517236429545 |
| 27 | 1737102081962 |
| 28 | 5845077156189 |
| 29 | 19702791805126 |
[1,0,1,2,5,14,39,114,339,1028,3163,9852,31005, 98436,314901,1014070,3284657,10694314,34979667, 114887846,378750951,1252865288,4157150327, 13832926200,46148704121,154327715592,517236429545, 1737102081962,5845077156189,19702791805126] |