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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 57 |
| 5 | 185 |
| 6 | 837 |
| 7 | 2937 |
| 8 | 13469 |
| 9 | 50053 |
| 10 | 231217 |
| 11 | 890229 |
| 12 | 4139401 |
| 13 | 16354421 |
| 14 | 76393849 |
| 15 | 307792285 |
| 16 | 1443118481 |
| 17 | 5903933641 |
| 18 | 27765120645 |
| 19 | 115004559193 |
| 20 | 542206182909 |
| 21 | 2268903801801 |
| 22 | 10719898112253 |
| 23 | 45245504677105 |
| 24 | 214162624027061 |
| 25 | 910577580645457 |
| 26 | 4316931291076229 |
| 27 | 18471685550254169 |
[1,1,5,13,57,185,837,2937,13469,50053,231217, 890229,4139401,16354421,76393849,307792285, 1443118481,5903933641,27765120645,115004559193, 542206182909,2268903801801,10719898112253, 45245504677105,214162624027061,910577580645457, 4316931291076229,18471685550254169] |