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 | 13 |
| 2 | 223 |
| 3 | 3331 |
| 4 | 44449 |
| 5 | 555557 |
| 6 | 66666629 |
| 7 | 777777701 |
| 8 | 888888883 |
| 9 | 99999999907 |
| 10 | 1010101010101010101039 |
| 11 | 11111111111111111111111 |
| 12 | 12121212121212121212121223 |
| 13 | 1313131313131313131313131301 |
| 14 | 141414141414141414141414141497 |
| 15 | 15151515151515151515151515151501 |