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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 45 |
| 5 | 120 |
| 6 | 331 |
| 7 | 855 |
| 8 | 2214 |
| 9 | 5545 |
| 10 | 13741 |
| 11 | 33362 |
| 12 | 80091 |
| 13 | 189339 |
| 14 | 442799 |
| 15 | 1023192 |
| 16 | 2340904 |
| 17 | 5302061 |
| 18 | 11902618 |
| 19 | 26488454 |
| 20 | 58479965 |
| 21 | 128120214 |
| 22 | 278680698 |
| 23 | 602009786 |
| 24 | 1292027222 |
| 25 | 2755684669 |
| 26 | 5842618668 |
| 27 | 12317175320 |
| 28 | 25825429276 |
| 29 | 53865355154 |
| 30 | 111786084504 |
| 31 | 230867856903 |
| 32 | 474585792077 |
| 33 | 971209629993 |
[1,5,15,45,120,331,855,2214,5545,13741,33362, 80091,189339,442799,1023192,2340904,5302061, 11902618,26488454,58479965,128120214,278680698, 602009786,1292027222,2755684669,5842618668, 12317175320,25825429276,53865355154,111786084504, 230867856903,474585792077,971209629993] |