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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 24 |
| 6 | 55 |
| 7 | 128 |
| 8 | 300 |
| 9 | 700 |
| 10 | 1632 |
| 11 | 3809 |
| 12 | 8890 |
| 13 | 20744 |
| 14 | 48406 |
| 15 | 112960 |
| 16 | 263599 |
| 17 | 615120 |
| 18 | 1435416 |
| 19 | 3349624 |
| 20 | 7816528 |
| 21 | 18240289 |
| 22 | 42564706 |
| 23 | 99327052 |
| 24 | 231785058 |
| 25 | 540883000 |
| 26 | 1262179815 |
| 27 | 2945365040 |
| 28 | 6873169028 |
| 29 | 16038912628 |
[0,1,2,4,10,24,55,128,300,700,1632,3809,8890, 20744,48406,112960,263599,615120,1435416,3349624, 7816528,18240289,42564706,99327052,231785058, 540883000,1262179815,2945365040,6873169028, 16038912628] |