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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 5 |
| 4 | 17 |
| 5 | 36 |
| 6 | 87 |
| 7 | 198 |
| 8 | 464 |
| 9 | 1075 |
| 10 | 2503 |
| 11 | 5815 |
| 12 | 13522 |
| 13 | 31431 |
| 14 | 73072 |
| 15 | 169868 |
| 16 | 394899 |
| 17 | 918025 |
| 18 | 2134153 |
| 19 | 4961300 |
| 20 | 11533627 |
| 21 | 26812426 |
| 22 | 62331332 |
| 23 | 144902763 |
| 24 | 336858059 |
| 25 | 783099975 |
| 26 | 1820486578 |
| 27 | 4232117835 |
| 28 | 9838480332 |
| 29 | 22871691896 |
| 30 | 53170232867 |
[0,3,5,17,36,87,198,464,1075,2503,5815,13522, 31431,73072,169868,394899,918025,2134153,4961300, 11533627,26812426,62331332,144902763,336858059, 783099975,1820486578,4232117835,9838480332, 22871691896,53170232867] |