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 | 120 |
| 2 | 8960 |
| 3 | 537600 |
| 4 | 28471296 |
| 5 | 1393459200 |
| 6 | 64678789120 |
| 7 | 2892811468800 |
| 8 | 125971743113216 |
| 9 | 5378780147220480 |
| 10 | 226309257119662080 |
| 11 | 9416205124868505600 |
| 12 | 388454135575280091136 |
| 13 | 15919881384987941928960 |