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) |
|---|---|
| 0 | 1 |
| 1 | 919 |
| 2 | 99199 |
| 3 | 9991999 |
| 4 | 999919999 |
| 5 | 99999199999 |
| 6 | 9999991999999 |
| 7 | 999999919999999 |
| 8 | 99999999199999999 |
| 9 | 9999999991999999999 |
| 10 | 999999999919999999999 |
| 11 | 99999999999199999999999 |
| 12 | 9999999999991999999999999 |
| 13 | 999999999999919999999999999 |
| 14 | 99999999999999199999999999999 |
| 15 | 9999999999999991999999999999999 |