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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 21 |
| 3 | 55 |
| 4 | 755 |
| 5 | 6393 |
| 6 | 60841 |
| 7 | 591585 |
| 8 | 5880829 |
| 9 | 58383932 |
| 10 | 585233819 |
| 11 | 5854941545 |
| 12 | 58759934077 |
| 13 | 589360075403 |
| 14 | 5914609427757 |
| 15 | 59355963113549 |
| 16 | 595731234612875 |
| 17 | 5979121155775603 |
| 18 | 60011713256358774 |
| 19 | 602331412174313879 |
[1,21,55,755,6393,60841,591585,5880829,58383932, 585233819,5854941545,58759934077,589360075403, 5914609427757,59355963113549,595731234612875, 5979121155775603,60011713256358774, 602331412174313879] |