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 | 40 |
| 2 | -322 |
| 3 | -166640 |
| 4 | -4808948 |
| 5 | 1088770400 |
| 6 | 89764806280 |
| 7 | -8965108001600 |
| 8 | -1566300023755120 |
| 9 | 75195499682396800 |
| 10 | 30101677798211937760 |
| 11 | -241190391967188985600 |
| 12 | -646057287688484347545920 |
| 13 | -20279476307208127137958400 |
| 14 | 15331208337896144822264021120 |