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 | 1 |
| 2 | 8 |
| 3 | 78 |
| 4 | 984 |
| 5 | 15480 |
| 6 | 292320 |
| 7 | 6441120 |
| 8 | 162207360 |
| 9 | 4595512320 |
| 10 | 144662112000 |
| 11 | 5009199148800 |
| 12 | 189221439052800 |
| 13 | 7743449813299200 |
| 14 | 341258374762905600 |
| 15 | 16113703632009984000 |
| 16 | 811588993992032256000 |
| 17 | 43431603596770701312000 |