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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 35 |
| 5 | 132 |
| 6 | 519 |
| 7 | 2105 |
| 8 | 8746 |
| 9 | 37033 |
| 10 | 159229 |
| 11 | 693343 |
| 12 | 3051290 |
| 13 | 13550083 |
| 14 | 60642857 |
| 15 | 273248824 |
| 16 | 1238567263 |
| 17 | 5643738611 |
| 18 | 25837579578 |
| 19 | 118785766683 |
| 20 | 548182891007 |
| 21 | 2538522337214 |
| 22 | 11792272546723 |
| 23 | 54936210525388 |
[1,1,3,10,35,132,519,2105,8746,37033,159229, 693343,3051290,13550083,60642857,273248824, 1238567263,5643738611,25837579578,118785766683, 548182891007,2538522337214,11792272546723, 54936210525388] |