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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 4 |
| 6 | 38 |
| 7 | 40 |
| 8 | 104 |
| 9 | 114 |
| 10 | 135 |
| 11 | 417 |
| 12 | 1251 |
| 13 | 14786 |
| 14 | 16720 |
| 15 | 43831 |
| 16 | 152659 |
[0,1,2,3,4,38,40,104,114,135,417,1251,14786,16720, 43831,152659] |