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 | 7 |
| 2 | 77377 |
| 3 | 7772777 |
| 4 | 777767777 |
| 5 | 77777677777 |
| 6 | 7777774777777 |
| 7 | 777777727777777 |
| 8 | 77777777677777777 |
| 9 | 77777777704777777777 |
| 10 | 777777777727777777777 |
| 11 | 77777777777677777777777 |
| 12 | 7777777777772777777777777 |
| 13 | 777777777777757777777777777 |