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 | 3 |
| 2 | 11 |
| 3 | 113 |
| 4 | 1117 |
| 5 | 11113 |
| 6 | 111119 |
| 7 | 1111151 |
| 8 | 11111117 |
| 9 | 111111113 |
| 10 | 1111111139 |
| 11 | 11111111113 |
| 12 | 111111111337 |
| 13 | 1111111111139 |
| 14 | 11111111111533 |
| 15 | 111111111111713 |
| 16 | 1111111111111153 |
| 17 | 11111111111111119 |
| 18 | 111111111111111131 |
| 19 | 1111111111111111111 |
| 20 | 11111111111111111131 |