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 | 1 |
| 2 | 11 |
| 3 | 161 |
| 4 | 1661 |
| 5 | 16161 |
| 6 | 161161 |
| 7 | 1618161 |
| 8 | 16188161 |
| 9 | 161808161 |
| 10 | 1618008161 |
| 11 | 16180308161 |
| 12 | 161803308161 |
| 13 | 1618033308161 |
| 14 | 16180333308161 |
| 15 | 161803393308161 |
| 16 | 1618033993308161 |
| 17 | 16180339893308161 |
| 18 | 161803398893308161 |
| 19 | 1618033988893308161 |
| 20 | 16180339888893308161 |
| 21 | 161803398878893308161 |