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 | 9 |
| 2 | 199 |
| 3 | 2999 |
| 4 | 39999 |
| 5 | 499999 |
| 6 | 5999999 |
| 7 | 69999999 |
| 8 | 799999999 |
| 9 | 8999999999 |
| 10 | 99999999999 |
| 11 | 1099999999999 |
| 12 | 11999999999999 |
| 13 | 129999999999999 |
| 14 | 1399999999999999 |
| 15 | 14999999999999999 |
| 16 | 159999999999999999 |
| 17 | 1699999999999999999 |
| 18 | 17999999999999999999 |
| 19 | 189999999999999999999 |
| 20 | 1999999999999999999999 |