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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 343 |
| 4 | 1981 |
| 5 | 9191 |
| 6 | 41083 |
| 7 | 181885 |
| 8 | 819099 |
| 9 | 3749921 |
| 10 | 17338503 |
| 11 | 80437853 |
| 12 | 373008019 |
| 13 | 1727505765 |
| 14 | 7991536851 |
| 15 | 36949011409 |
| 16 | 170810543525 |
| 17 | 789678726959 |
| 18 | 3651141596711 |
| 19 | 16882484843753 |
| 20 | 78065155382933 |
| 21 | 360977446471839 |
[7,49,343,1981,9191,41083,181885,819099,3749921, 17338503,80437853,373008019,1727505765,7991536851, 36949011409,170810543525,789678726959, 3651141596711,16882484843753,78065155382933, 360977446471839] |