| n | a(n) |
|---|---|
| 2 | 23 |
| 3 | 307 |
| 4 | 4001 |
| 5 | 50021 |
| 6 | 600011 |
| 7 | 7000003 |
| 8 | 80000023 |
| 9 | 900000011 |
| 10 | 1000000007 |
| 11 | 11000000021 |
| 12 | 120000000007 |
| 13 | 1300000000021 |
| 14 | 14000000000003 |
| 15 | 150000000000007 |
| 16 | 1600000000000007 |
| 17 | 17000000000000009 |
| 18 | 180000000000000029 |
[23,307,4001,50021,600011,7000003,80000023, 900000011,1000000007,11000000021,120000000007, 1300000000021,14000000000003,150000000000007, 1600000000000007,17000000000000009, 180000000000000029] |