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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 28 |
| 5 | 96 |
| 6 | 349 |
| 7 | 1266 |
| 8 | 4872 |
| 9 | 18937 |
| 10 | 74824 |
| 11 | 300666 |
| 12 | 1221397 |
| 13 | 5003868 |
| 14 | 20748125 |
| 15 | 86640057 |
| 16 | 363955361 |
| 17 | 1541316904 |
| 18 | 6561178732 |
| 19 | 28057372888 |
| 20 | 120671313034 |
| 21 | 521071872996 |
| 22 | 2258015020869 |
| 23 | 9827393809110 |
| 24 | 42906980263767 |
| 25 | 187868103415443 |
| 26 | 825367631777135 |
| 27 | 3635500398284390 |
| 28 | 16050904740944003 |
[1,1,3,8,28,96,349,1266,4872,18937,74824,300666, 1221397,5003868,20748125,86640057,363955361, 1541316904,6561178732,28057372888,120671313034, 521071872996,2258015020869,9827393809110, 42906980263767,187868103415443,825367631777135, 3635500398284390,16050904740944003] |