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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 11 |
| 8 | 25 |
| 9 | 58 |
| 10 | 135 |
| 11 | 317 |
| 12 | 750 |
| 13 | 1785 |
| 14 | 4272 |
| 15 | 10275 |
| 16 | 24823 |
| 17 | 60210 |
| 18 | 146576 |
| 19 | 358010 |
| 20 | 877087 |
| 21 | 2154751 |
| 22 | 5307166 |
| 23 | 13102511 |
| 24 | 32418806 |
| 25 | 80375267 |
| 26 | 199650310 |
| 27 | 496803811 |
| 28 | 1238276667 |
| 29 | 3091173482 |
| 30 | 7727893389 |
| 31 | 19346109435 |
| 32 | 48493869237 |
[1,0,0,1,1,2,5,11,25,58,135,317,750,1785,4272, 10275,24823,60210,146576,358010,877087,2154751, 5307166,13102511,32418806,80375267,199650310, 496803811,1238276667,3091173482,7727893389, 19346109435,48493869237] |