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 | 3 |
| 2 | 12 |
| 3 | 51 |
| 4 | 226 |
| 5 | 1026 |
| 6 | 4733 |
| 7 | 22083 |
| 8 | 103914 |
| 9 | 492228 |
| 10 | 2344035 |
| 11 | 11211210 |
| 12 | 53817063 |
| 13 | 259135299 |
| 14 | 1251074772 |
| 15 | 6053946531 |
| 16 | 29354128498 |
| 17 | 142584834924 |
| 18 | 693691007267 |
| 19 | 3379680991356 |
| 20 | 16486985580693 |
| 21 | 80521218046569 |
| 22 | 393674826425462 |