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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 4 |
| 5 | 13 |
| 6 | 34 |
| 7 | 84 |
| 8 | 116 |
| 9 | 382 |
| 10 | 1384 |
| 11 | 1984 |
| 12 | 2498 |
| 13 | 7102 |
| 14 | 11944 |
| 15 | 22276 |
| 16 | 65242 |
| 17 | 105118 |
| 18 | 186574 |
| 19 | 414001 |
| 20 | 888856 |
[1,1,2,4,4,13,34,84,116,382,1384,1984,2498,7102, 11944,22276,65242,105118,186574,414001,888856] |