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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 11 |
| 8 | 26 |
| 9 | 62 |
| 10 | 148 |
| 11 | 356 |
| 12 | 860 |
| 13 | 2085 |
| 14 | 5073 |
| 15 | 12382 |
| 16 | 30309 |
| 17 | 74391 |
| 18 | 183042 |
| 19 | 451427 |
| 20 | 1115741 |
| 21 | 2763228 |
| 22 | 6856327 |
| 23 | 17042633 |
| 24 | 42433166 |
| 25 | 105816857 |
| 26 | 264268595 |
| 27 | 660908408 |
| 28 | 1655040445 |
| 29 | 4149700172 |
| 30 | 10416866219 |
| 31 | 26178412875 |
| 32 | 65858360172 |
| 33 | 165850637772 |
[0,0,0,1,1,2,5,11,26,62,148,356,860,2085,5073, 12382,30309,74391,183042,451427,1115741,2763228, 6856327,17042633,42433166,105816857,264268595, 660908408,1655040445,4149700172,10416866219, 26178412875,65858360172,165850637772] |