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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 44 |
| 6 | 154 |
| 7 | 514 |
| 8 | 1949 |
| 9 | 7100 |
| 10 | 28289 |
| 11 | 109269 |
| 12 | 450989 |
| 13 | 1814897 |
| 14 | 7692208 |
| 15 | 31909424 |
| 16 | 138042852 |
| 17 | 586240058 |
| 18 | 2577374384 |
| 19 | 11152156893 |
| 20 | 49670880217 |
| 21 | 218216089703 |
| 22 | 982348019505 |
| 23 | 4370272299508 |
| 24 | 19850169852979 |
| 25 | 89244498210728 |
| 26 | 408439137023100 |
| 27 | 1852782584365454 |
| 28 | 8534857228606366 |
[1,1,2,5,15,44,154,514,1949,7100,28289,109269, 450989,1814897,7692208,31909424,138042852, 586240058,2577374384,11152156893,49670880217, 218216089703,982348019505,4370272299508, 19850169852979,89244498210728,408439137023100, 1852782584365454,8534857228606366] |