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 | 40320 |
| 2 | 81729648000 |
| 3 | 369398958888960000 |
| 4 | 2390461829733887910000000 |
| 5 | 18975581770994682860770223800320 |
| 6 | 171889289584866507880743491472699801600 |