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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 33 |
| 5 | 121 |
| 6 | 468 |
| 7 | 1859 |
| 8 | 7558 |
| 9 | 31270 |
| 10 | 131330 |
| 11 | 558115 |
| 12 | 2396603 |
| 13 | 10379648 |
| 14 | 45292679 |
| 15 | 198926208 |
| 16 | 878692550 |
| 17 | 3900981744 |
| 18 | 17396764823 |
| 19 | 77896353911 |
| 20 | 350065380105 |
| 21 | 1578398595372 |
| 22 | 7138256186788 |
| 23 | 32371596240950 |
| 24 | 147175354377729 |
| 25 | 670685606484390 |
| 26 | 3062947647863016 |
| 27 | 14016157023522647 |
[1,1,3,9,33,121,468,1859,7558,31270,131330,558115, 2396603,10379648,45292679,198926208,878692550, 3900981744,17396764823,77896353911,350065380105, 1578398595372,7138256186788,32371596240950, 147175354377729,670685606484390,3062947647863016, 14016157023522647] |