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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 76 |
| 3 | 368 |
| 4 | 2070 |
| 5 | 8523 |
| 6 | 30558 |
| 7 | 100761 |
| 8 | 313108 |
| 9 | 921941 |
| 10 | 2585664 |
| 11 | 6949146 |
| 12 | 18004266 |
| 13 | 45195087 |
| 14 | 110356035 |
| 15 | 262913226 |
| 16 | 612588113 |
| 17 | 1398558018 |
| 18 | 3133356168 |
| 19 | 6897689403 |
| 20 | 14935630967 |
| 21 | 31839486936 |
| 22 | 66877133838 |
| 23 | 138505092333 |
| 24 | 283012794327 |
[20,76,368,2070,8523,30558,100761,313108,921941, 2585664,6949146,18004266,45195087,110356035, 262913226,612588113,1398558018,3133356168, 6897689403,14935630967,31839486936,66877133838, 138505092333,283012794327] |