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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 59 |
| 4 | 171 |
| 5 | 1019 |
| 6 | 3051 |
| 7 | 15291 |
| 8 | 43691 |
| 9 | 262139 |
| 10 | 786411 |
| 11 | 3932091 |
| 12 | 11271851 |
| 13 | 66845691 |
| 14 | 200010731 |
| 15 | 1002159035 |
| 16 | 2863311531 |
| 17 | 17179869179 |
| 18 | 51539607531 |
| 19 | 257698037691 |
| 20 | 738734374571 |
| 21 | 4380866640891 |
| 22 | 13108240182251 |
| 23 | 65678639872955 |
| 24 | 187655711009451 |
[1,3,11,59,171,1019,3051,15291,43691,262139, 786411,3932091,11271851,66845691,200010731, 1002159035,2863311531,17179869179,51539607531, 257698037691,738734374571,4380866640891, 13108240182251,65678639872955,187655711009451] |