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 | 0 |
| 2 | 0 |
| 3 | 449 |
| 4 | 4999 |
| 5 | 44449 |
| 6 | 444449 |
| 7 | 4444949 |
| 8 | 44444999 |
| 9 | 444499949 |
| 10 | 4444444999 |
| 11 | 44444449949 |
| 12 | 444444494449 |
| 13 | 4444449444949 |
| 14 | 44444444449499 |
| 15 | 444444444499499 |
| 16 | 4444444444444999 |
| 17 | 44444444444444999 |
| 18 | 444444444449449949 |