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 | 2 |
| 2 | 8 |
| 3 | 24 |
| 4 | 144 |
| 5 | 720 |
| 6 | 5760 |
| 7 | 40320 |
| 8 | 362880 |
| 9 | 3991680 |
| 10 | 39916800 |
| 11 | 518918400 |
| 12 | 6227020800 |
| 13 | 105859353600 |
| 14 | 1482030950400 |
| 15 | 28158588057600 |
| 16 | 422378820864000 |
| 17 | 9714712879872000 |
| 18 | 155435406077952000 |
| 19 | 4507626776260608000 |