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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 26 |
| 3 | 15 |
| 4 | 20 |
| 5 | 55 |
| 6 | 201 |
| 7 | 337 |
| 8 | 1359 |
| 9 | 5918 |
| 10 | 13840 |
| 11 | 50917 |
| 12 | 214418 |
| 13 | 640869 |
| 14 | 2276124 |
| 15 | 8928543 |
| 16 | 29953696 |
| 17 | 106456744 |
| 18 | 399005390 |
| 19 | 1401253518 |
| 20 | 5009804395 |
| 21 | 18368049681 |
| 22 | 65601194194 |
| 23 | 235509869390 |
| 24 | 855175501812 |
| 25 | 3072957989537 |
| 26 | 11056497704449 |
[1,26,15,20,55,201,337,1359,5918,13840,50917, 214418,640869,2276124,8928543,29953696,106456744, 399005390,1401253518,5009804395,18368049681, 65601194194,235509869390,855175501812, 3072957989537,11056497704449] |