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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 13 |
| 3 | 54 |
| 4 | 216 |
| 5 | 867 |
| 6 | 3469 |
| 7 | 13878 |
| 8 | 55512 |
| 9 | 222051 |
| 10 | 888205 |
| 11 | 3552822 |
| 12 | 14211288 |
| 13 | 56845155 |
| 14 | 227380621 |
| 15 | 909522486 |
| 16 | 3638089944 |
| 17 | 14552359779 |
| 18 | 58209439117 |
| 19 | 232837756470 |
| 20 | 931351025880 |
| 21 | 3725404103523 |
| 22 | 14901616414093 |
| 23 | 59606465656374 |
[3,13,54,216,867,3469,13878,55512,222051,888205, 3552822,14211288,56845155,227380621,909522486, 3638089944,14552359779,58209439117,232837756470, 931351025880,3725404103523,14901616414093, 59606465656374] |