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 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 105 |
| 4 | 27030 |
| 5 | 1771476585 |
| 6 | 7608434000728254870 |
| 7 | 140350834813144189858090274002849666665 |
| 8 | 47758914269546354982683078068829456704164423862093743397580034411621752859030 |