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 | 73 |
| 3 | 773 |
| 4 | 7757 |
| 5 | 77773 |
| 6 | 777737 |
| 7 | 7777753 |
| 8 | 77777377 |
| 9 | 777777773 |
| 10 | 7777777577 |
| 11 | 77777777573 |
| 12 | 777777777773 |
| 13 | 7777777777573 |
| 14 | 77777777777753 |
| 15 | 777777777777773 |
| 16 | 7777777777777753 |
| 17 | 77777777777775557 |
| 18 | 777777777777777737 |
| 19 | 7777777777777777577 |
| 20 | 77777777777777777257 |
| 21 | 777777777777777777773 |
| 22 | 7777777777777777773533 |
| 23 | 77777777777777777775353 |