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 | 21 |
| 3 | 27 |
| 4 | 81 |
| 5 | 315 |
| 6 | 849 |
| 7 | 1893 |
| 8 | 2883 |
| 9 | 9591 |
| 10 | 14691 |