This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 7 |
| 5 | 61 |
| 6 | 83 |
| 7 | 383 |
| 8 | 727 |
| 9 | 72727 |
| 10 | 94949 |
| 11 | 1616161 |
| 12 | 383838383 |
| 13 | 727272727 |
| 14 | 383838383838383 |
| 15 | 38383838383838383 |
| 16 | 72727272727272727 |
| 17 | 94949494949494949 |
| 18 | 383838383838383838383 |