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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 26 |
| 6 | 101 |
| 7 | 412 |
| 8 | 1738 |
| 9 | 7514 |
| 10 | 33126 |
| 11 | 148358 |
| 12 | 673094 |
| 13 | 3087076 |
| 14 | 14289509 |
| 15 | 66669232 |
| 16 | 313199848 |
| 17 | 1480261250 |
| 18 | 7033516168 |
| 19 | 33579194044 |
| 20 | 160996913287 |
| 21 | 774875393390 |
| 22 | 3742454218020 |
| 23 | 18132421559672 |
| 24 | 88107253715627 |
| 25 | 429260108473000 |
| 26 | 2096482108251547 |
[1,1,2,7,26,101,412,1738,7514,33126,148358,673094, 3087076,14289509,66669232,313199848,1480261250, 7033516168,33579194044,160996913287,774875393390, 3742454218020,18132421559672,88107253715627, 429260108473000,2096482108251547] |