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| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 255 |
| 3 | 826 |
| 4 | 2823 |
| 5 | 9815 |
| 6 | 34996 |
| 7 | 125469 |
| 8 | 457125 |
| 9 | 1664894 |
| 10 | 6142099 |
| 11 | 22586567 |
| 12 | 84018940 |
| 13 | 311018349 |
| 14 | 1163797285 |
| 15 | 4328792462 |
| 16 | 16268051859 |
| 17 | 60722854295 |
| 18 | 228929149516 |
| 19 | 856718666317 |
| 20 | 3237411387189 |
| 21 | 12138170248222 |
| 22 | 45946152057331 |
[81,255,826,2823,9815,34996,125469,457125,1664894, 6142099,22586567,84018940,311018349,1163797285, 4328792462,16268051859,60722854295,228929149516, 856718666317,3237411387189,12138170248222, 45946152057331] |