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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 22 |
| 5 | 68 |
| 6 | 241 |
| 7 | 974 |
| 8 | 4410 |
| 9 | 21969 |
| 10 | 118698 |
| 11 | 688301 |
| 12 | 4250788 |
[1,3,8,22,68,241,974,4410,21969,118698,688301, 4250788] |