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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 10 |
| 5 | 30 |
| 6 | 180 |
| 7 | 585 |
| 8 | 1430 |
| 9 | 3575 |
| 10 | 9100 |
| 11 | 31850 |
| 12 | 83300 |
| 13 | 220150 |
| 14 | 792540 |
| 15 | 11888100 |
| 16 | 32167800 |
| 17 | 87567900 |
| 18 | 1576222200 |
| 19 | 4334611050 |
| 20 | 11971782900 |
| 21 | 33194488950 |
| 22 | 92367273600 |
| 23 | 257858638800 |
| 24 | 722004188640 |
| 25 | 18050104716000 |
[1,1,2,5,10,30,180,585,1430,3575,9100,31850,83300, 220150,792540,11888100,32167800,87567900, 1576222200,4334611050,11971782900,33194488950, 92367273600,257858638800,722004188640, 18050104716000] |