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 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 124 |
| 5 | 4620 |
| 6 | 536360 |
| 7 | 189313340 |
| 8 | 201653395768 |
| 9 | 651683788574786 |