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 | 5 |
| 2 | 59 |
| 3 | 599 |
| 4 | 59999 |
| 5 | 95959 |
| 6 | 99559 |
| 7 | 599959 |
| 8 | 599999 |
| 9 | 995959 |
| 10 | 999599 |
| 11 | 999959 |
| 12 | 5595559 |
| 13 | 5595599 |
| 14 | 5599999 |
| 15 | 5955959 |
| 16 | 5995999 |
| 17 | 5999599 |
| 18 | 9555599 |
| 19 | 9559999 |
| 20 | 9595559 |
| 21 | 9955559 |
| 22 | 9995599 |
| 23 | 55555559 |
| 24 | 55559599 |
| 25 | 55595599 |
| 26 | 55599959 |
| 27 | 55959559 |
| 28 | 59999999 |
| 29 | 95559559 |