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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 15 |
| 6 | 36 |
| 7 | 94 |
| 8 | 256 |
| 9 | 729 |
| 10 | 2154 |
| 11 | 6583 |
| 12 | 20736 |
| 13 | 67156 |
| 14 | 223150 |
| 15 | 759375 |
| 16 | 2642246 |
| 17 | 9387369 |
| 18 | 34012224 |
| 19 | 125537306 |
| 20 | 471556032 |
| 21 | 1801088541 |
| 22 | 6989288907 |
| 23 | 27536796143 |
| 24 | 110075314176 |
| 25 | 446169698824 |
| 26 | 1832746290156 |
| 27 | 7625597484987 |
| 28 | 32122422687591 |
[1,2,3,6,15,36,94,256,729,2154,6583,20736,67156, 223150,759375,2642246,9387369,34012224,125537306, 471556032,1801088541,6989288907,27536796143, 110075314176,446169698824,1832746290156, 7625597484987,32122422687591] |