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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 43 |
| 6 | 147 |
| 7 | 575 |
| 8 | 2648 |
| 9 | 14617 |
| 10 | 96696 |
| 11 | 754585 |
| 12 | 6794015 |
| 13 | 69116493 |
| 14 | 781266266 |
| 15 | 9688636317 |
| 16 | 130551322618 |
| 17 | 1897079161639 |
| 18 | 29549030800315 |
| 19 | 490880073850267 |
| 20 | 8660360684895644 |
| 21 | 161671375033644161 |
| 22 | 3183279386216962364 |
[1,1,2,5,14,43,147,575,2648,14617,96696,754585, 6794015,69116493,781266266,9688636317, 130551322618,1897079161639,29549030800315, 490880073850267,8660360684895644, 161671375033644161,3183279386216962364] |