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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 10 |
| 3 | 19 |
| 4 | 31 |
| 5 | 61 |
| 6 | 211 |
| 7 | 181 |
| 8 | 361 |
| 9 | 631 |
| 10 | 841 |
| 11 | 1261 |
| 12 | 5461 |
| 13 | 2521 |
| 14 | 6931 |
| 15 | 18481 |
| 16 | 20791 |
| 17 | 13861 |
| 18 | 27721 |
| 19 | 41581 |
| 20 | 83161 |
| 21 | 138601 |
| 22 | 245701 |
| 23 | 235621 |
| 24 | 180181 |
| 25 | 556921 |
| 26 | 360361 |
| 27 | 540541 |
| 28 | 1670761 |
| 29 | 1081081 |
| 30 | 1413721 |
| 31 | 2162161 |
| 32 | 3603601 |
| 33 | 4324321 |
| 34 | 3063061 |
[4,10,19,31,61,211,181,361,631,841,1261,5461,2521, 6931,18481,20791,13861,27721,41581,83161,138601, 245701,235621,180181,556921,360361,540541,1670761, 1081081,1413721,2162161,3603601,4324321,3063061] |