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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 45 |
| 5 | 197 |
| 6 | 903 |
| 7 | 4279 |
| 8 | 20792 |
| 9 | 103044 |
| 10 | 518864 |
| 11 | 2647244 |
| 12 | 13657284 |
[1,3,11,45,197,903,4279,20792,103044,518864, 2647244,13657284] |