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 | 3 |
| 3 | 7 |
| 4 | 9 |
| 5 | 19 |
| 6 | 21 |
| 7 | 57 |
| 8 | 63 |
| 9 | 133 |
| 10 | 171 |
| 11 | 399 |
| 12 | 1197 |
| 13 | 928163 |
| 14 | 2784489 |
| 15 | 6497141 |
| 16 | 8353467 |
| 17 | 17635097 |
| 18 | 19491423 |
| 19 | 52905291 |
| 20 | 58474269 |
| 21 | 123445679 |
| 22 | 158715873 |
| 23 | 370337037 |
| 24 | 1111011111 |
| 25 | 1111211111 |
| 26 | 3333633333 |
| 27 | 7778477777 |
| 28 | 10000899999 |
| 29 | 21113011109 |