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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 23 |
| 5 | 84 |
| 6 | 331 |
| 7 | 1367 |
| 8 | 5812 |
| 9 | 25331 |
| 10 | 112804 |
| 11 | 511045 |
| 12 | 2348042 |
| 13 | 10919414 |
| 14 | 51313463 |
| 15 | 243332340 |
| 16 | 1163105227 |
| 17 | 5598774334 |
| 18 | 27119990519 |
| 19 | 132107355553 |
| 20 | 646793104859 |
| 21 | 3181256110699 |
| 22 | 15712610146876 |
| 23 | 77903855239751 |
| 24 | 387609232487489 |
| 25 | 1934788962992123 |
[1,1,2,7,23,84,331,1367,5812,25331,112804,511045, 2348042,10919414,51313463,243332340,1163105227, 5598774334,27119990519,132107355553,646793104859, 3181256110699,15712610146876,77903855239751, 387609232487489,1934788962992123] |