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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 28 |
| 5 | 77 |
| 6 | 328 |
| 7 | 1032 |
| 8 | 4561 |
| 9 | 15405 |
| 10 | 69863 |
| 11 | 247581 |
| 12 | 1139957 |
| 13 | 4191007 |
| 14 | 19505310 |
| 15 | 73723498 |
| 16 | 345996567 |
| 17 | 1336688246 |
| 18 | 6313660360 |
| 19 | 24830303768 |
| 20 | 117888042833 |
| 21 | 470535221695 |
| 22 | 2243426487708 |
| 23 | 9066875262306 |
| 24 | 43381843668078 |
| 25 | 177214005001044 |
| 26 | 850444498221412 |
| 27 | 3506406506099757 |
| 28 | 16870406935037750 |
[1,1,3,7,28,77,328,1032,4561,15405,69863,247581, 1139957,4191007,19505310,73723498,345996567, 1336688246,6313660360,24830303768,117888042833, 470535221695,2243426487708,9066875262306, 43381843668078,177214005001044,850444498221412, 3506406506099757,16870406935037750] |