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 | 90 |
| 2 | 656100 |
| 3 | 387420489000 |
| 4 | 18530201888518410000 |
| 5 | 71789798769185258877024900000 |
| 6 | 22528399544939174411840147874772641000000 |