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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 24 |
| 3 | 113 |
| 4 | 526 |
| 5 | 2430 |
| 6 | 11166 |
| 7 | 51105 |
| 8 | 233190 |
| 9 | 1061510 |
| 10 | 4822984 |
| 11 | 21879786 |
| 12 | 99135076 |
| 13 | 448707992 |
| 14 | 2029215114 |
| 15 | 9170247393 |
| 16 | 41416383366 |
| 17 | 186957126702 |
| 18 | 843575853984 |
| 19 | 3804927658878 |
| 20 | 17156636097156 |
| 21 | 77339426905812 |
[1,5,24,113,526,2430,11166,51105,233190,1061510, 4822984,21879786,99135076,448707992,2029215114, 9170247393,41416383366,186957126702,843575853984, 3804927658878,17156636097156,77339426905812] |