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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 33 |
| 5 | 187 |
| 6 | 723 |
| 7 | 3265 |
| 8 | 14451 |
| 9 | 63707 |
| 10 | 282753 |
| 11 | 1249731 |
| 12 | 5531139 |
| 13 | 24469121 |
| 14 | 108250899 |
| 15 | 478918091 |
| 16 | 2118744609 |
| 17 | 9373518211 |
| 18 | 41469120051 |
| 19 | 183462579393 |
| 20 | 811652664051 |
| 21 | 3590813514139 |
| 22 | 15886035617793 |
| 23 | 70281041695555 |
| 24 | 310928730092451 |
| 25 | 1375572596332481 |
| 26 | 6085638870654099 |
[1,3,15,33,187,723,3265,14451,63707,282753, 1249731,5531139,24469121,108250899,478918091, 2118744609,9373518211,41469120051,183462579393, 811652664051,3590813514139,15886035617793, 70281041695555,310928730092451,1375572596332481, 6085638870654099] |