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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 59 |
| 4 | 366 |
| 5 | 2332 |
| 6 | 15121 |
| 7 | 99276 |
| 8 | 657894 |
| 9 | 4391438 |
| 10 | 29482320 |
| 11 | 198865680 |
| 12 | 1346655921 |
| 13 | 9149295482 |
| 14 | 62336961732 |
| 15 | 425760311734 |
| 16 | 2914151872614 |
| 17 | 19983724103726 |
| 18 | 137267022656710 |
| 19 | 944287970305935 |
| 20 | 6504676822047876 |
| 21 | 44861522295224400 |
| 22 | 309742638630690264 |
[1,2,10,59,366,2332,15121,99276,657894,4391438, 29482320,198865680,1346655921,9149295482, 62336961732,425760311734,2914151872614, 19983724103726,137267022656710,944287970305935, 6504676822047876,44861522295224400, 309742638630690264] |