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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 39 |
| 3 | 324 |
| 4 | 2799 |
| 5 | 24999 |
| 6 | 228570 |
| 7 | 2124999 |
| 8 | 19999999 |
| 9 | 189999999 |
| 10 | 1818181817 |
| 11 | 17499999999 |
| 12 | 169230769229 |
| 13 | 1642857142856 |
| 14 | 15999999999999 |
| 15 | 156249999999999 |
| 16 | 1529411764705881 |
| 17 | 14999999999999999 |
| 18 | 147368421052631577 |
| 19 | 1449999999999999999 |
| 20 | 14285714285714285713 |
[4,39,324,2799,24999,228570,2124999,19999999, 189999999,1818181817,17499999999,169230769229, 1642857142856,15999999999999,156249999999999, 1529411764705881,14999999999999999, 147368421052631577,1449999999999999999, 14285714285714285713] |