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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 36 |
| 4 | 168 |
| 5 | 737 |
| 6 | 3582 |
| 7 | 16548 |
| 8 | 81032 |
| 9 | 382762 |
| 10 | 1890435 |
| 11 | 9071907 |
| 12 | 44923827 |
| 13 | 217534842 |
| 14 | 1080563215 |
| 15 | 5269297335 |
| 16 | 26206186223 |
| 17 | 128382787217 |
| 18 | 639395569356 |
| 19 | 3144154838613 |
| 20 | 15669351408709 |
| 21 | 77258894907688 |
| 22 | 385315579777762 |
| 23 | 1904096710220571 |
| 24 | 9500036064922626 |
| 25 | 47025429577566991 |
| 26 | 234722271569474468 |
[1,2,9,36,168,737,3582,16548,81032,382762,1890435, 9071907,44923827,217534842,1080563215,5269297335, 26206186223,128382787217,639395569356, 3144154838613,15669351408709,77258894907688, 385315579777762,1904096710220571,9500036064922626, 47025429577566991,234722271569474468] |