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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 64 |
| 5 | 340 |
| 6 | 1903 |
| 7 | 11053 |
| 8 | 65992 |
| 9 | 402508 |
| 10 | 2497207 |
| 11 | 15709873 |
| 12 | 99980007 |
| 13 | 642535004 |
| 14 | 4164018953 |
| 15 | 27181480712 |
| 16 | 178559253274 |
| 17 | 1179546465168 |
| 18 | 7830695860690 |
| 19 | 52216823047741 |
| 20 | 349584244515573 |
| 21 | 2348869478981267 |
| 22 | 15833924106623011 |
| 23 | 107057382854642578 |
| 24 | 725829177205070854 |
[1,1,3,13,64,340,1903,11053,65992,402508,2497207, 15709873,99980007,642535004,4164018953, 27181480712,178559253274,1179546465168, 7830695860690,52216823047741,349584244515573, 2348869478981267,15833924106623011, 107057382854642578,725829177205070854] |