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 | 1 |
| 2 | 5550101001 |
| 3 | 15500001001 |
| 4 | 115501010001005110501011001 |
| 5 | 555115055501101055005101001 |
| 6 | 550015110551505101015151115110001 |