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 | 2178 |
| 2 | 21978 |
| 3 | 219978 |
| 4 | 2199978 |
| 5 | 21782178 |
| 6 | 21999978 |
| 7 | 217802178 |
| 8 | 219999978 |
| 9 | 2178002178 |
| 10 | 2197821978 |
| 11 | 2199999978 |
| 12 | 21780002178 |
| 13 | 21978021978 |
| 14 | 21999999978 |
| 15 | 217800002178 |
| 16 | 217821782178 |
| 17 | 219780021978 |
| 18 | 219978219978 |
| 19 | 219999999978 |
| 20 | 2178000002178 |
| 21 | 2178219782178 |