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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 15 |
| 6 | 84 |
| 7 | 330 |
| 8 | 1812 |
| 9 | 9978 |
| 10 | 65503 |
| 11 | 449719 |
| 12 | 3674670 |
| 13 | 28886593 |
| 14 | 266242729 |
| 15 | 2527701273 |
| 16 | 25749021720 |