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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 16 |
| 6 | 60 |
| 7 | 298 |
| 8 | 1948 |
| 9 | 16460 |
| 10 | 179801 |
| 11 | 2540520 |
| 12 | 46485494 |
| 13 | 1101504593 |
| 14 | 33766488831 |
| 15 | 1336910042036 |
| 16 | 68237302714204 |
| 17 | 4481677081035893 |
[1,2,3,6,16,60,298,1948,16460,179801,2540520, 46485494,1101504593,33766488831,1336910042036, 68237302714204,4481677081035893] |