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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 38 |
| 5 | 161 |
| 6 | 718 |
| 7 | 3385 |
| 8 | 16548 |
| 9 | 83183 |
| 10 | 427490 |
| 11 | 2237196 |
| 12 | 11865560 |
| 13 | 63677761 |
[1,3,10,38,161,718,3385,16548,83183,427490, 2237196,11865560,63677761] |