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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 66 |
| 4 | 212 |
| 5 | 921 |
| 6 | 4086 |
| 7 | 17332 |
| 8 | 75122 |
| 9 | 326124 |
| 10 | 1408419 |
| 11 | 6097753 |
| 12 | 26404858 |
| 13 | 114255411 |
| 14 | 494519798 |
| 15 | 2140532037 |
| 16 | 9264510866 |
| 17 | 40098753497 |
| 18 | 173557720814 |
| 19 | 751196491106 |
| 20 | 3251349837567 |
| 21 | 14072600064116 |
| 22 | 60909443628883 |
| 23 | 263630086389334 |
| 24 | 1141051836433576 |
| 25 | 4938735140721662 |
[2,12,66,212,921,4086,17332,75122,326124,1408419, 6097753,26404858,114255411,494519798,2140532037, 9264510866,40098753497,173557720814,751196491106, 3251349837567,14072600064116,60909443628883, 263630086389334,1141051836433576,4938735140721662] |