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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 8 |
| 6 | 20 |
| 7 | 55 |
| 8 | 159 |
| 9 | 464 |
| 10 | 1383 |
| 11 | 4200 |
| 12 | 12910 |
| 13 | 40112 |
| 14 | 125832 |
| 15 | 397888 |
| 16 | 1266848 |
| 17 | 4058263 |
| 18 | 13070453 |
| 19 | 42297553 |
| 20 | 137467673 |
| 21 | 448499679 |
| 22 | 1468388784 |
| 23 | 4822816903 |
| 24 | 15886282268 |
| 25 | 52468807845 |
| 26 | 173718343364 |
| 27 | 576466929104 |
| 28 | 1916968549390 |
| 29 | 6387086400663 |
| 30 | 21319636605919 |
| 31 | 71284279000874 |
| 32 | 238724756808108 |
| 33 | 800659887614429 |
| 34 | 2689098091847122 |
[1,1,1,3,8,20,55,159,464,1383,4200,12910,40112, 125832,397888,1266848,4058263,13070453,42297553, 137467673,448499679,1468388784,4822816903, 15886282268,52468807845,173718343364,576466929104, 1916968549390,6387086400663,21319636605919, 71284279000874,238724756808108,800659887614429, 2689098091847122] |