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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 102 |
| 5 | 421 |
| 6 | 1826 |
| 7 | 8034 |
| 8 | 36106 |
| 9 | 164248 |
| 10 | 755561 |
| 11 | 3506429 |
| 12 | 16389676 |
| 13 | 77084134 |
| 14 | 364407891 |
| 15 | 1730410838 |
| 16 | 8248698860 |
| 17 | 39452993279 |
| 18 | 189262877746 |
| 19 | 910308265005 |
| 20 | 4388634690019 |
| 21 | 21202183937455 |
| 22 | 102624744762164 |
| 23 | 497583258709272 |
| 24 | 2416313479214622 |
| 25 | 11750478490536311 |
| 26 | 57216349110310344 |
| 27 | 278933752655062431 |
[1,2,7,25,102,421,1826,8034,36106,164248,755561, 3506429,16389676,77084134,364407891,1730410838, 8248698860,39452993279,189262877746,910308265005, 4388634690019,21202183937455,102624744762164, 497583258709272,2416313479214622, 11750478490536311,57216349110310344, 278933752655062431] |