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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 15 |
| 3 | 60 |
| 4 | 295 |
| 5 | 1625 |
| 6 | 9430 |
| 7 | 56465 |
| 8 | 345010 |
| 9 | 2139595 |
| 10 | 13419500 |
| 11 | 84926105 |
| 12 | 541398665 |
| 13 | 3472389210 |
| 14 | 22385362895 |
| 15 | 144945232375 |
| 16 | 942089445030 |
| 17 | 6143582084115 |
| 18 | 40181143112035 |
| 19 | 263482860974570 |
| 20 | 1731780213622125 |
| 21 | 11406235045261205 |
| 22 | 75268685723935940 |
[1,5,15,60,295,1625,9430,56465,345010,2139595, 13419500,84926105,541398665,3472389210, 22385362895,144945232375,942089445030, 6143582084115,40181143112035,263482860974570, 1731780213622125,11406235045261205, 75268685723935940] |