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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 17 |
| 4 | 71 |
| 5 | 275 |
| 6 | 1197 |
| 7 | 5015 |
| 8 | 22283 |
| 9 | 96237 |
| 10 | 432479 |
| 11 | 1908495 |
| 12 | 8659109 |
| 13 | 38763863 |
| 14 | 177016943 |
| 15 | 800411443 |
| 16 | 3674033371 |
| 17 | 16740426241 |
| 18 | 77162216045 |
| 19 | 353660756327 |
| 20 | 1635698336915 |
| 21 | 7532360479213 |
| 22 | 34938080545161 |
| 23 | 161509862609757 |
| 24 | 750995241429291 |
| 25 | 3482801514066409 |
| 26 | 16229200948512393 |
| 27 | 75468695084619587 |
[1,1,5,17,71,275,1197,5015,22283,96237,432479, 1908495,8659109,38763863,177016943,800411443, 3674033371,16740426241,77162216045,353660756327, 1635698336915,7532360479213,34938080545161, 161509862609757,750995241429291,3482801514066409, 16229200948512393,75468695084619587] |