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 | 2 |
| 2 | 4 |
| 3 | 18 |
| 4 | 172 |
| 5 | 978 |
| 6 | 3672 |
| 7 | 11034 |
| 8 | 27241 |
| 9 | 60804 |
| 10 | 122741 |
| 11 | 232138 |
| 12 | 412263 |
| 13 | 697058 |