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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 28 |
| 4 | 102 |
| 5 | 378 |
| 6 | 1390 |
| 7 | 5229 |
| 8 | 19785 |
| 9 | 74761 |
| 10 | 283143 |
| 11 | 1073820 |
| 12 | 4072442 |
| 13 | 15617469 |
| 14 | 59967564 |
| 15 | 230081349 |
| 16 | 889342557 |
| 17 | 3443431566 |
| 18 | 13326462430 |
| 19 | 51756384099 |
| 20 | 201245258853 |
| 21 | 782441280159 |
| 22 | 3052080395712 |
| 23 | 11914099660794 |
| 24 | 46498675915560 |
[1,3,9,28,102,378,1390,5229,19785,74761,283143, 1073820,4072442,15617469,59967564,230081349, 889342557,3443431566,13326462430,51756384099, 201245258853,782441280159,3052080395712, 11914099660794,46498675915560] |