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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 4 |
| 6 | 4 |
| 7 | 11 |
| 8 | 15 |
| 9 | 25 |
| 10 | 32 |
| 11 | 64 |
| 12 | 88 |
| 13 | 155 |
| 14 | 234 |
| 15 | 423 |
| 16 | 647 |
| 17 | 1184 |
| 18 | 1800 |
[1,1,1,2,2,4,4,11,15,25,32,64,88,155,234,423,647, 1184,1800] |