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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 14 |
| 7 | 40 |
| 8 | 168 |
| 9 | 873 |
| 10 | 5632 |
| 11 | 63538 |
| 12 | 1026354 |
| 13 | 20200595 |
| 14 | 622554839 |
| 15 | 29122695476 |
| 16 | 1747360635695 |
| 17 | 149225079090933 |
[1,1,1,3,7,14,40,168,873,5632,63538,1026354, 20200595,622554839,29122695476,1747360635695, 149225079090933] |