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 | 19 |
| 2 | 199 |
| 3 | 919 |
| 4 | 991 |
| 5 | 1999 |
| 6 | 9199 |
| 7 | 99991 |
| 8 | 199999 |
| 9 | 991999 |
| 10 | 999199 |
| 11 | 9999991 |
| 12 | 19999999 |
| 13 | 99991999 |
| 14 | 9199999999 |
| 15 | 11111111911 |
| 16 | 11119111111 |
| 17 | 99999199999 |
| 18 | 99999991999 |
| 19 | 111111911191 |
| 20 | 111191119111 |
| 21 | 111911191111 |
| 22 | 191119111111 |
| 23 | 991999999999 |
| 24 | 999999991999 |
| 25 | 1111111119919 |
| 26 | 1111111191199 |
| 27 | 1111111191919 |
| 28 | 1111111199119 |