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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 33 |
| 6 | 104 |
| 7 | 339 |
| 8 | 1133 |
| 9 | 3861 |
| 10 | 13364 |
| 11 | 46852 |
| 12 | 166022 |
| 13 | 593674 |
| 14 | 2139552 |
| 15 | 7763305 |
| 16 | 28337265 |
| 17 | 103981965 |
| 18 | 383351580 |
| 19 | 1419269280 |
| 20 | 5274495930 |
| 21 | 19669409790 |
| 22 | 73580417040 |
| 23 | 276043317030 |
| 24 | 1038327097314 |
| 25 | 3915101867778 |
| 26 | 14795310818024 |
| 27 | 56028144245304 |
| 28 | 212581753906508 |
| 29 | 808027815817012 |
[2,4,11,33,104,339,1133,3861,13364,46852,166022, 593674,2139552,7763305,28337265,103981965, 383351580,1419269280,5274495930,19669409790, 73580417040,276043317030,1038327097314, 3915101867778,14795310818024,56028144245304, 212581753906508,808027815817012] |