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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 5 |
| 5 | 10 |
| 6 | 25 |
| 7 | 79 |
| 8 | 318 |
| 9 | 1637 |
| 10 | 10753 |
| 11 | 89872 |
| 12 | 955537 |
| 13 | 12930173 |
| 14 | 222618066 |
| 15 | 4874855543 |
| 16 | 135781292309 |
| 17 | 4811103270054 |
| 18 | 216847500834513 |
| 19 | 12432143862756779 |
| 20 | 906625645142897790 |
| 21 | 84102571511631809865 |
[1,1,2,3,5,10,25,79,318,1637,10753,89872,955537, 12930173,222618066,4874855543,135781292309, 4811103270054,216847500834513,12432143862756779, 906625645142897790,84102571511631809865] |