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 | 122 |
| 3 | 1784993 |
| 4 | 3162420494366 |
| 5 | 677889092180295554010 |
| 6 | 17582706239031734855147601736020 |
| 7 | 55182061625844132594149408768243237640344385 |