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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 16 |
| 5 | 112 |
| 6 | 1020 |
| 7 | 10209 |
| 8 | 109673 |
| 9 | 1225914 |
| 10 | 14137194 |
| 11 | 166972947 |
| 12 | 2011515207 |
[1,1,3,16,112,1020,10209,109673,1225914,14137194, 166972947,2011515207] |