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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 8 |
| 7 | 22 |
| 8 | 55 |
| 9 | 145 |
| 10 | 386 |
| 11 | 1039 |
| 12 | 2837 |
| 13 | 7808 |
| 14 | 21693 |
| 15 | 60697 |
| 16 | 170959 |
| 17 | 484306 |
| 18 | 1379020 |
| 19 | 3944780 |
| 20 | 11330962 |
| 21 | 32668988 |
| 22 | 94510169 |
| 23 | 274262571 |
| 24 | 798153211 |
| 25 | 2328830794 |
| 26 | 6811354123 |
| 27 | 19966156857 |
| 28 | 58647721275 |
| 29 | 172600025350 |
| 30 | 508870577560 |
| 31 | 1502795261440 |
[1,3,1,1,4,8,22,55,145,386,1039,2837,7808,21693, 60697,170959,484306,1379020,3944780,11330962, 32668988,94510169,274262571,798153211,2328830794, 6811354123,19966156857,58647721275,172600025350, 508870577560,1502795261440] |