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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 44 |
| 6 | 148 |
| 7 | 528 |
| 8 | 1972 |
| 9 | 7647 |
| 10 | 30605 |
| 11 | 125801 |
| 12 | 529131 |
| 13 | 2270481 |
| 14 | 9914870 |
| 15 | 43973755 |
| 16 | 197744417 |
| 17 | 900327160 |
| 18 | 4145285618 |
| 19 | 19280282194 |
| 20 | 90507546094 |
| 21 | 428476211848 |
| 22 | 2044274855774 |
| 23 | 9823314566417 |
| 24 | 47516954475991 |
| 25 | 231260870664189 |
[1,1,2,5,14,44,148,528,1972,7647,30605,125801, 529131,2270481,9914870,43973755,197744417, 900327160,4145285618,19280282194,90507546094, 428476211848,2044274855774,9823314566417, 47516954475991,231260870664189] |