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 | 22 |
| 6 | 92 |
| 7 | 420 |
| 8 | 2042 |
| 9 | 10404 |
| 10 | 54954 |
| 11 | 298648 |
| 12 | 1660714 |
| 13 | 9410772 |
| 14 | 54174212 |
| 15 | 316038060 |
| 16 | 1864781388 |
| 17 | 11111804604 |
| 18 | 66782160002 |
| 19 | 404392312896 |
| 20 | 2465100947836 |
| 21 | 15116060536540 |
| 22 | 93184874448186 |
| 23 | 577198134479356 |
| 24 | 3590697904513792 |
| 25 | 22425154536754776 |