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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 14 |
| 5 | 44 |
| 6 | 158 |
| 7 | 535 |
| 8 | 1821 |
| 9 | 6092 |
| 10 | 20000 |
| 11 | 66378 |
| 12 | 220957 |
| 13 | 733556 |
| 14 | 2436430 |
| 15 | 8095687 |
| 16 | 26892148 |
| 17 | 89338832 |
| 18 | 296769545 |
| 19 | 985760656 |
| 20 | 3274702309 |
| 21 | 10878267642 |
| 22 | 36136741115 |
[1,2,7,14,44,158,535,1821,6092,20000,66378,220957, 733556,2436430,8095687,26892148,89338832, 296769545,985760656,3274702309,10878267642, 36136741115] |