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 | 7523 |
| 5 | 77323 |
| 6 | 753773 |
| 7 | 7732337 |
| 8 | 77323733 |
| 9 | 773337223 |
| 10 | 7773337223 |
| 11 | 77735235323 |
| 12 | 777352335323 |
| 13 | 7773232237523 |
| 14 | 77733372233533 |
| 15 | 777352353232333 |
| 16 | 7773733335332333 |
| 17 | 77737523727333737 |
| 18 | 777733372232237537 |
| 19 | 7777352335323753353 |
| 20 | 77773733335332333773 |