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 | 7 |
| 1 | 79 |
| 2 | 799 |
| 3 | 7999 |
| 4 | 79999 |
| 5 | 799999 |
| 6 | 7999999 |
| 7 | 79999999 |
| 8 | 799999999 |
| 9 | 7999999999 |
| 10 | 79999999999 |
| 11 | 799999999999 |
| 12 | 7999999999999 |
| 13 | 79999999999999 |
| 14 | 799999999999999 |
| 15 | 7999999999999999 |
| 16 | 79999999999999999 |
| 17 | 799999999999999999 |
| 18 | 7999999999999999999 |
| 19 | 79999999999999999999 |
| 20 | 799999999999999999999 |