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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 80 |
| 6 | 318 |
| 7 | 1305 |
| 8 | 5487 |
| 9 | 23535 |
| 10 | 102603 |
| 11 | 453400 |
| 12 | 2026408 |
| 13 | 9144361 |
| 14 | 41607161 |
| 15 | 190675552 |
| 16 | 879318056 |
| 17 | 4077566276 |
| 18 | 19001732690 |
| 19 | 88940105945 |
| 20 | 417948841012 |
| 21 | 1971086634986 |
| 22 | 9326180071850 |
| 23 | 44258248464408 |
| 24 | 210605264950063 |
| 25 | 1004694354945863 |
| 26 | 4804017049287049 |