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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 59 |
| 5 | 214 |
| 6 | 823 |
| 7 | 3214 |
| 8 | 12749 |
| 9 | 51824 |
| 10 | 213137 |
| 11 | 886409 |
| 12 | 3730703 |
| 13 | 15807766 |
| 14 | 67446457 |
| 15 | 289940695 |
| 16 | 1253403583 |
| 17 | 5447204342 |
| 18 | 23787645787 |
| 19 | 104271410457 |
| 20 | 458794416353 |
| 21 | 2026181571486 |
| 22 | 8977296628629 |
| 23 | 39895424941238 |
| 24 | 177774668991073 |
| 25 | 794060282751084 |
| 26 | 3555147578359925 |
| 27 | 15953110208570535 |
[1,2,5,17,59,214,823,3214,12749,51824,213137, 886409,3730703,15807766,67446457,289940695, 1253403583,5447204342,23787645787,104271410457, 458794416353,2026181571486,8977296628629, 39895424941238,177774668991073,794060282751084, 3555147578359925,15953110208570535] |