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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 19 |
| 4 | 65 |
| 5 | 222 |
| 6 | 776 |
| 7 | 2682 |
| 8 | 9310 |
| 9 | 32288 |
| 10 | 112036 |
| 11 | 388710 |
| 12 | 1348756 |
| 13 | 4679860 |
| 14 | 16238178 |
| 15 | 56343110 |
| 16 | 195499228 |
| 17 | 678342902 |
| 18 | 2353713428 |
| 19 | 8166912404 |
| 20 | 28337544624 |
| 21 | 98325585264 |
| 22 | 341170022526 |
| 23 | 1183791422522 |
| 24 | 4107518363162 |
| 25 | 14252263353112 |
[2,6,19,65,222,776,2682,9310,32288,112036,388710, 1348756,4679860,16238178,56343110,195499228, 678342902,2353713428,8166912404,28337544624, 98325585264,341170022526,1183791422522, 4107518363162,14252263353112] |