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 | 151 |
| 2 | 353 |
| 3 | 757 |
| 4 | 15551 |
| 5 | 75557 |
| 6 | 355555553 |
| 7 | 75555555557 |
| 8 | 155555555555555555551 |
| 9 | 755555555555555555557 |
| 10 | 75555555555555555555557 |
| 11 | 155555555555555555555555555555551 |
| 12 | 75555555555555555555555555555555555555555555555555555555557 |