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 | 9 |
| 4 | 15 |
| 5 | 33 |
| 6 | 63 |
| 7 | 75 |
| 8 | 225 |
| 9 | 243 |
| 10 | 273 |
| 11 | 453 |
| 12 | 813 |
| 13 | 1275 |
| 14 | 1443 |
| 15 | 2763 |
| 16 | 3003 |
| 17 | 6693 |
| 18 | 9933 |
| 19 | 10515 |