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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 53 |
| 4 | 260 |
| 5 | 1156 |
| 6 | 4845 |
| 7 | 19551 |
| 8 | 76912 |
| 9 | 297275 |
| 10 | 1134705 |
| 11 | 4292145 |
| 12 | 16128061 |
| 13 | 60304951 |
| 14 | 224660626 |
| 15 | 834641671 |
| 16 | 3094322026 |
| 17 | 11453607152 |
| 18 | 42344301686 |
| 19 | 156404021389 |
| 20 | 577291806894 |
| 21 | 2129654436910 |
| 22 | 7853149169635 |
| 23 | 28949515515376 |
| 24 | 106692395098433 |
| 25 | 393137817645838 |
[1,9,53,260,1156,4845,19551,76912,297275,1134705, 4292145,16128061,60304951,224660626,834641671, 3094322026,11453607152,42344301686,156404021389, 577291806894,2129654436910,7853149169635, 28949515515376,106692395098433,393137817645838] |