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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 51 |
| 5 | 221 |
| 6 | 993 |
| 7 | 4530 |
| 8 | 20939 |
| 9 | 97285 |
| 10 | 455133 |
| 11 | 2140073 |
| 12 | 10109361 |
| 13 | 47933432 |
| 14 | 227989548 |
| 15 | 1087308518 |
| 16 | 5197510491 |
| 17 | 24895494553 |
| 18 | 119461041021 |
| 19 | 574151728723 |
| 20 | 2763435409221 |
| 21 | 13317800106750 |
| 22 | 64257410265249 |
| 23 | 310367127210417 |
| 24 | 1500548876309897 |
| 25 | 7261253691617671 |
[1,3,13,51,221,993,4530,20939,97285,455133, 2140073,10109361,47933432,227989548,1087308518, 5197510491,24895494553,119461041021,574151728723, 2763435409221,13317800106750,64257410265249, 310367127210417,1500548876309897,7261253691617671] |