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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 17 |
| 3 | 103 |
| 4 | 643 |
| 5 | 4082 |
| 6 | 26193 |
| 7 | 169324 |
| 8 | 1100561 |
| 9 | 7183179 |
| 10 | 47037770 |
| 11 | 308839996 |
| 12 | 2032250927 |
| 13 | 13397582173 |
| 14 | 88463267588 |
| 15 | 584916078291 |
| 16 | 3872067079555 |
| 17 | 25659566239274 |
| 18 | 170200888987121 |
| 19 | 1129893804436178 |
| 20 | 7506551997419770 |
| 21 | 49904474883265592 |
| 22 | 331976969392263124 |
[1,3,17,103,643,4082,26193,169324,1100561,7183179, 47037770,308839996,2032250927,13397582173, 88463267588,584916078291,3872067079555, 25659566239274,170200888987121,1129893804436178, 7506551997419770,49904474883265592, 331976969392263124] |