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 | 5 |
| 3 | 7400 |
| 4 | 1515608208000 |
| 5 | 67968144879431450715389952000 |
| 6 | 2618461740951506934762583974466059060153960058218086400000 |