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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 44 |
| 6 | 146 |
| 7 | 530 |
| 8 | 1975 |
| 9 | 7314 |
| 10 | 27262 |
| 11 | 102802 |
| 12 | 390138 |
| 13 | 1486064 |
| 14 | 5682756 |
| 15 | 21812436 |
| 16 | 83976075 |
| 17 | 324115550 |
| 18 | 1253795510 |
| 19 | 4859960402 |
| 20 | 18871869302 |
| 21 | 73398851448 |
| 22 | 285882923196 |
| 23 | 1114943553308 |
| 24 | 4353426835238 |
| 25 | 17016813133124 |
| 26 | 66581653586476 |
| 27 | 260750813149140 |
| 28 | 1022023318047220 |
[1,1,3,13,44,146,530,1975,7314,27262,102802, 390138,1486064,5682756,21812436,83976075, 324115550,1253795510,4859960402,18871869302, 73398851448,285882923196,1114943553308, 4353426835238,17016813133124,66581653586476, 260750813149140,1022023318047220] |