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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 28 |
| 5 | 80 |
| 6 | 247 |
| 7 | 793 |
| 8 | 2558 |
| 9 | 8550 |
| 10 | 29174 |
| 11 | 99856 |
| 12 | 348717 |
| 13 | 1233071 |
| 14 | 4370391 |
| 15 | 15686057 |
| 16 | 56763062 |
| 17 | 205799392 |
| 18 | 752476359 |
| 19 | 2767134060 |
| 20 | 10192178158 |
| 21 | 37765951585 |
| 22 | 140525915462 |
| 23 | 523621511694 |
| 24 | 1959695454184 |
| 25 | 7357711578218 |
| 26 | 27658399144870 |
| 27 | 104318355674896 |
| 28 | 394433880972610 |
| 29 | 1492987311881850 |
[1,2,4,10,28,80,247,793,2558,8550,29174,99856, 348717,1233071,4370391,15686057,56763062, 205799392,752476359,2767134060,10192178158, 37765951585,140525915462,523621511694, 1959695454184,7357711578218,27658399144870, 104318355674896,394433880972610,1492987311881850] |