| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 5 |
| 3 | 7 |
| 4 | 9 |
| 5 | 11 |
| 6 | 19 |
| 7 | 21 |
| 8 | 31 |
| 9 | 33 |
| 10 | 39 |
| 11 | 49 |
| 12 | 51 |
| 13 | 81 |
| 14 | 99 |
| 15 | 101 |
| 16 | 123 |
| 17 | 129 |
| 18 | 159 |
| 19 | 171 |
| 20 | 177 |
| 21 | 189 |
| 22 | 231 |
| 23 | 291 |
| 24 | 441 |
| 25 | 879 |
| 26 | 1011 |
| 27 | 2751 |
[4,5,7,9,11,19,21,31,33,39,49,51,81,99,101,123, 129,159,171,177,189,231,291,441,879,1011,2751] |