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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 5 |
| 6 | 25 |
| 7 | 102 |
| 8 | 410 |
| 9 | 1545 |
| 10 | 5784 |
| 11 | 21015 |
| 12 | 76248 |
| 13 | 272377 |
| 14 | 974208 |
| 15 | 3455177 |
| 16 | 12287351 |
| 17 | 43502174 |
| 18 | 154554897 |
| 19 | 547955950 |
| 20 | 1950335934 |
| 21 | 6937352521 |
| 22 | 24777223885 |
| 23 | 88515560121 |
| 24 | 317513893877 |
| 25 | 1139848959317 |
| 26 | 4108296484542 |
| 27 | 14823490668322 |
| 28 | 53689879422115 |
| 29 | 194704264528116 |
[1,5,25,102,410,1545,5784,21015,76248,272377, 974208,3455177,12287351,43502174,154554897, 547955950,1950335934,6937352521,24777223885, 88515560121,317513893877,1139848959317, 4108296484542,14823490668322,53689879422115, 194704264528116] |