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 | 4 |
| 3 | 14 |
| 4 | 57 |
| 5 | 247 |
| 6 | 1124 |
| 7 | 5296 |
| 8 | 25621 |
| 9 | 126529 |
| 10 | 635264 |
| 11 | 3232886 |
| 12 | 16638821 |
| 13 | 86456767 |
| 14 | 452927448 |
| 15 | 2389672752 |
| 16 | 12686560409 |
| 17 | 67721774737 |
| 18 | 363268546892 |
| 19 | 1957131383342 |
| 20 | 10585610149121 |
| 21 | 57458399978455 |
| 22 | 312890905815900 |
| 23 | 1708883398754176 |
| 24 | 9358483855106829 |
| 25 | 51378142520487281 |
| 26 | 282714583026982504 |