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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 31 |
| 4 | 134 |
| 5 | 594 |
| 6 | 2695 |
| 7 | 12443 |
| 8 | 58013 |
| 9 | 273231 |
| 10 | 1294901 |
| 11 | 6173085 |
| 12 | 29558960 |
| 13 | 142080867 |
| 14 | 685104615 |
| 15 | 3312474950 |
| 16 | 16053281812 |
| 17 | 77956368977 |
| 18 | 379237613129 |
| 19 | 1847783768699 |
| 20 | 9015632064590 |
| 21 | 44043527415973 |
| 22 | 215404646524976 |
| 23 | 1054552809431666 |
| 24 | 5167513805355012 |
| 25 | 25343121317598360 |
| 26 | 124386470702241908 |
[1,2,8,31,134,594,2695,12443,58013,273231,1294901, 6173085,29558960,142080867,685104615,3312474950, 16053281812,77956368977,379237613129, 1847783768699,9015632064590,44043527415973, 215404646524976,1054552809431666,5167513805355012, 25343121317598360,124386470702241908] |