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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 18 |
| 3 | 92 |
| 4 | 458 |
| 5 | 1982 |
| 6 | 7928 |
| 7 | 28592 |
| 8 | 95138 |
| 9 | 292993 |
| 10 | 845027 |
| 11 | 2295322 |
| 12 | 5915631 |
| 13 | 14535676 |
| 14 | 34224682 |
| 15 | 77510148 |
| 16 | 169459010 |
| 17 | 358698558 |
| 18 | 737106306 |
| 19 | 1473867060 |
| 20 | 2873564862 |
| 21 | 5472731212 |
| 22 | 10198198452 |
| 23 | 18621343624 |
| 24 | 33361303957 |
| 25 | 58713103696 |
[1,3,18,92,458,1982,7928,28592,95138,292993, 845027,2295322,5915631,14535676,34224682,77510148, 169459010,358698558,737106306,1473867060, 2873564862,5472731212,10198198452,18621343624, 33361303957,58713103696] |