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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 23 |
| 4 | 100 |
| 5 | 368 |
| 6 | 1710 |
| 7 | 6716 |
| 8 | 31823 |
| 9 | 130061 |
| 10 | 623003 |
| 11 | 2611508 |
| 12 | 12616721 |
| 13 | 53820289 |
| 14 | 261699739 |
| 15 | 1131097502 |
| 16 | 5525211564 |
| 17 | 24129146559 |
| 18 | 118255755796 |
| 19 | 520778209686 |
| 20 | 2558745315274 |
| 21 | 11346116005601 |
| 22 | 55860667523716 |
| 23 | 249129364575265 |
| 24 | 1228616735554889 |
| 25 | 5506312402878732 |
| 26 | 27193271314477361 |
| 27 | 122388911479518502 |
[1,2,7,23,100,368,1710,6716,31823,130061,623003, 2611508,12616721,53820289,261699739,1131097502, 5525211564,24129146559,118255755796,520778209686, 2558745315274,11346116005601,55860667523716, 249129364575265,1228616735554889,5506312402878732, 27193271314477361,122388911479518502] |