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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 40 |
| 4 | 149 |
| 5 | 564 |
| 6 | 2166 |
| 7 | 8420 |
| 8 | 33074 |
| 9 | 131085 |
| 10 | 523599 |
| 11 | 2105727 |
| 12 | 8519469 |
| 13 | 34652696 |
| 14 | 141621164 |
| 15 | 581266730 |
| 16 | 2394961851 |
| 17 | 9902433681 |
| 18 | 41074316737 |
| 19 | 170869972460 |
| 20 | 712729001716 |
| 21 | 2980264528670 |
| 22 | 12490379959184 |
| 23 | 52458339164169 |
[1,3,11,40,149,564,2166,8420,33074,131085,523599, 2105727,8519469,34652696,141621164,581266730, 2394961851,9902433681,41074316737,170869972460, 712729001716,2980264528670,12490379959184, 52458339164169] |