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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | 1 |
| 4 | 3 |
| 5 | 2 |
| 6 | 7 |
| 7 | 5 |
| 8 | 20 |
| 9 | 15 |
| 10 | 67 |
| 11 | 52 |
| 12 | 255 |
| 13 | 203 |
| 14 | 1080 |
| 15 | 877 |
| 16 | 5017 |
| 17 | 4140 |
| 18 | 25287 |
| 19 | 21147 |
| 20 | 137122 |
| 21 | 115975 |
| 22 | 794545 |
| 23 | 678570 |
| 24 | 4892167 |
| 25 | 4213597 |
| 26 | 31858034 |
| 27 | 27644437 |
| 28 | 218543759 |
| 29 | 190899322 |
| 30 | 1573857867 |
| 31 | 1382958545 |
| 32 | 11863100692 |
| 33 | 10480142147 |
| 34 | 93345011951 |
| 35 | 82864869804 |
[0,0,2,1,3,2,7,5,20,15,67,52,255,203,1080,877, 5017,4140,25287,21147,137122,115975,794545,678570, 4892167,4213597,31858034,27644437,218543759, 190899322,1573857867,1382958545,11863100692, 10480142147,93345011951,82864869804] |