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 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 33 |
| 5 | 176 |
| 6 | 1254 |
| 7 | 8933 |
| 8 | 66825 |
| 9 | 519694 |
| 10 | 4138135 |
| 11 | 33767309 |
| 12 | 280876390 |
| 13 | 2372830737 |
| 14 | 20310411686 |
| 15 | 175820328509 |
| 16 | 1536914640835 |
| 17 | 13549491187945 |
| 18 | 120350669560296 |
| 19 | 1076119459308449 |
| 20 | 9679474365334444 |
| 21 | 87530988547642414 |
| 22 | 795367317696619250 |