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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 27 |
| 3 | 135 |
| 4 | 648 |
| 5 | 3159 |
| 6 | 15309 |
| 7 | 74358 |
| 8 | 360855 |
| 9 | 1751787 |
| 10 | 8503056 |
| 11 | 41275251 |
| 12 | 200353257 |
| 13 | 972537030 |
| 14 | 4720790403 |
| 15 | 22915204479 |
| 16 | 111232727064 |
| 17 | 539935021503 |
| 18 | 2620899608085 |
| 19 | 12722114017782 |
| 20 | 61754438526111 |
| 21 | 299762341738371 |
| 22 | 1455076971950112 |
| 23 | 7063091991495675 |
[1,6,27,135,648,3159,15309,74358,360855,1751787, 8503056,41275251,200353257,972537030,4720790403, 22915204479,111232727064,539935021503, 2620899608085,12722114017782,61754438526111, 299762341738371,1455076971950112,7063091991495675] |