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 | 4 |
| 3 | 51 |
| 4 | 1072 |
| 5 | 31845 |
| 6 | 1292616 |
| 7 | 68464207 |
| 8 | 4555593904 |
| 9 | 369790197705 |