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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 57 |
| 5 | 207 |
| 6 | 770 |
| 7 | 2928 |
| 8 | 11385 |
| 9 | 44761 |
| 10 | 178507 |
| 11 | 717723 |
| 12 | 2911567 |
| 13 | 11889471 |
| 14 | 48843018 |
| 15 | 201708227 |
| 16 | 836728300 |
| 17 | 3485203920 |
| 18 | 14568180657 |
| 19 | 61093715901 |
| 20 | 256943318442 |
| 21 | 1083492074350 |
| 22 | 4579868091028 |
| 23 | 19401361515390 |
| 24 | 82354213479878 |
| 25 | 350222446183284 |
| 26 | 1491926082298429 |
| 27 | 6365617368220411 |
[1,2,5,17,57,207,770,2928,11385,44761,178507, 717723,2911567,11889471,48843018,201708227, 836728300,3485203920,14568180657,61093715901, 256943318442,1083492074350,4579868091028, 19401361515390,82354213479878,350222446183284, 1491926082298429,6365617368220411] |