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 | 3 |
| 3 | 7 |
| 4 | 83 |
| 5 | 109950 |
| 6 | 28613442061634 |
| 7 | 32966964611113760521683249750048 |
| 8 | 623226477875973310927522916529663444655632673539934117923988862064800 |