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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 11 |
| 3 | 37 |
| 4 | 129 |
| 5 | 450 |
| 6 | 1568 |
| 7 | 5464 |
| 8 | 19041 |
| 9 | 66354 |
| 10 | 231230 |
| 11 | 805789 |
| 12 | 2808009 |
| 13 | 9785334 |
| 14 | 34099877 |
| 15 | 118831060 |
| 16 | 414101811 |
| 17 | 1443059667 |
| 18 | 5028766229 |
| 19 | 17524216333 |
| 20 | 61068290730 |
| 21 | 212810436816 |
| 22 | 741600615908 |
| 23 | 2584325664397 |
| 24 | 9005843571858 |
[3,11,37,129,450,1568,5464,19041,66354,231230, 805789,2808009,9785334,34099877,118831060, 414101811,1443059667,5028766229,17524216333, 61068290730,212810436816,741600615908, 2584325664397,9005843571858] |