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 | 3 |
| 2 | 13 |
| 3 | 31 |
| 4 | 113 |
| 5 | 131 |
| 6 | 311 |
| 7 | 11113 |
| 8 | 11131 |
| 9 | 11311 |
| 10 | 113111 |
| 11 | 131111 |
| 12 | 311111 |
| 13 | 11111131 |
| 14 | 11111311 |
| 15 | 11113111 |
| 16 | 11131111 |
| 17 | 111111113 |
| 18 | 111111131 |
| 19 | 111113111 |
| 20 | 131111111 |
| 21 | 11111111113 |
| 22 | 11111111131 |
| 23 | 11113111111 |
| 24 | 11131111111 |
| 25 | 31111111111 |