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 | 101101 |
| 2 | 102501 |
| 3 | 111111 |
| 4 | 112511 |
| 5 | 121151 |
| 6 | 122551 |