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 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 8 | 8 |
| 9 | 9 |
| 10 | 90 |
| 11 | 909 |
| 12 | 9090 |
| 13 | 90909 |
| 14 | 909090 |
| 15 | 9090909 |
| 16 | 90909090 |
| 17 | 909090909 |
| 18 | 9090909090 |
| 19 | 90909090909 |
| 20 | 909090909090 |
| 21 | 9090909090909 |
| 22 | 90909090909090 |
| 23 | 909090909090909 |
| 24 | 9090909090909090 |
| 25 | 90909090909090909 |
| 26 | 909090909090909090 |
| 27 | 9090909090909090909 |