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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 8 |
| 6 | 26 |
| 7 | 76 |
| 8 | 247 |
| 9 | 783 |
| 10 | 2565 |
| 11 | 8447 |
| 12 | 28256 |
| 13 | 95168 |
| 14 | 323720 |
| 15 | 1108415 |
| 16 | 3821144 |
| 17 | 13246307 |
| 18 | 46158480 |
| 19 | 161574043 |
| 20 | 567925140 |
| 21 | 2003653016 |
| 22 | 7092953340 |
| 23 | 25186731980 |
| 24 | 89690452750 |
| 25 | 320221033370 |
| 26 | 1146028762599 |
| 27 | 4110596336036 |
| 28 | 14774346783745 |
| 29 | 53203889807764 |
| 30 | 191934931634880 |
[1,1,1,3,8,26,76,247,783,2565,8447,28256,95168, 323720,1108415,3821144,13246307,46158480, 161574043,567925140,2003653016,7092953340, 25186731980,89690452750,320221033370, 1146028762599,4110596336036,14774346783745, 53203889807764,191934931634880] |