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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 19 |
| 7 | 55 |
| 8 | 130 |
| 9 | 284 |
| 10 | 712 |
| 11 | 1768 |
| 12 | 5795 |
| 13 | 17017 |
| 14 | 68263 |
| 15 | 195545 |
| 16 | 545258 |
| 17 | 1698179 |
| 18 | 11990404 |
| 19 | 28003819 |
| 20 | 99712613 |
| 21 | 452419979 |
| 22 | 1990586012 |
| 23 | 5313193818 |
| 24 | 22323360772 |
[1,2,4,10,19,55,130,284,712,1768,5795,17017,68263, 195545,545258,1698179,11990404,28003819,99712613, 452419979,1990586012,5313193818,22323360772] |