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 | 6 |
| 3 | 21 |
| 4 | 73 |
| 5 | 273 |
| 6 | 1049 |
| 7 | 4117 |
| 8 | 16416 |
| 9 | 66263 |
| 10 | 270211 |
| 11 | 1111443 |
| 12 | 4605575 |
| 13 | 19204920 |
| 14 | 80515734 |
| 15 | 339137432 |
| 16 | 1434319849 |