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 | 12 |
| 2 | 144 |
| 3 | 75516 |
| 4 | 4641494832 |
| 5 | 31335724079805792 |
| 6 | 24293081804978470413606900 |