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| n | a(n) |
|---|---|
| 1 | 21 |
| 2 | 105 |
| 3 | 2211 |
| 4 | 9045 |
| 5 | 222111 |
| 6 | 306153 |
| 7 | 742371 |
| 8 | 890445 |
| 9 | 1050525 |
| 10 | 22221111 |
| 11 | 88904445 |
| 12 | 107905395 |
| 13 | 173808690 |
| 14 | 2222211111 |
| 15 | 8889044445 |
| 16 | 12141260706 |
| 17 | 15754278771 |
| 18 | 222222111111 |
| 19 | 888890444445 |
| 20 | 22222221111111 |
| 21 | 36734701836735 |
| 22 | 65306123265306 |
[21,105,2211,9045,222111,306153,742371,890445, 1050525,22221111,88904445,107905395,173808690, 2222211111,8889044445,12141260706,15754278771, 222222111111,888890444445,22222221111111, 36734701836735,65306123265306] |