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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 20 |
| 7 | 48 |
| 8 | 114 |
| 9 | 284 |
| 10 | 714 |
| 11 | 1829 |
| 12 | 4731 |
| 13 | 12391 |
| 14 | 32711 |
| 15 | 87084 |
| 16 | 233349 |
| 17 | 629137 |
| 18 | 1705039 |
| 19 | 4642999 |
| 20 | 12696374 |
| 21 | 34851662 |
| 22 | 95997401 |
| 23 | 265253845 |
| 24 | 735035099 |
| 25 | 2042203194 |
| 26 | 5687771773 |
| 27 | 15876641362 |
| 28 | 44409566681 |
| 29 | 124460776515 |
| 30 | 349437246152 |
| 31 | 982732274507 |
[1,1,2,4,9,20,48,114,284,714,1829,4731,12391, 32711,87084,233349,629137,1705039,4642999, 12696374,34851662,95997401,265253845,735035099, 2042203194,5687771773,15876641362,44409566681, 124460776515,349437246152,982732274507] |