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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 59 |
| 5 | 229 |
| 6 | 965 |
| 7 | 4055 |
| 8 | 17519 |
| 9 | 76531 |
| 10 | 339617 |
| 11 | 1519317 |
| 12 | 6868085 |
| 13 | 31229275 |
| 14 | 143009551 |
| 15 | 658263313 |
| 16 | 3045358661 |
| 17 | 14151988831 |
| 18 | 66005473045 |
| 19 | 308942367881 |
| 20 | 1450529184419 |
| 21 | 6829913795115 |
| 22 | 32246590185049 |
| 23 | 152592323776307 |
| 24 | 723689890887601 |
| 25 | 3439065676087693 |
| 26 | 16373592066131361 |
| 27 | 78095727737074121 |
[1,1,5,15,59,229,965,4055,17519,76531,339617, 1519317,6868085,31229275,143009551,658263313, 3045358661,14151988831,66005473045,308942367881, 1450529184419,6829913795115,32246590185049, 152592323776307,723689890887601,3439065676087693, 16373592066131361,78095727737074121] |