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 | 1 |
| 3 | 5 |
| 4 | 24 |
| 5 | 133 |
| 6 | 846 |
| 7 | 5661 |
| 8 | 39556 |
| 9 | 286000 |
| 10 | 2123329 |
| 11 | 16112057 |
| 12 | 124512556 |
| 13 | 977227830 |
| 14 | 7772368380 |
| 15 | 62535450861 |
| 16 | 508271324688 |
| 17 | 4168218286276 |
| 18 | 34455941596060 |
| 19 | 286864341314320 |
| 20 | 2403705165816240 |
| 21 | 20258850167232165 |
| 22 | 171652324167433710 |
| 23 | 1461462393790971585 |
| 24 | 12498416291503945764 |