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 | -115920 |
| 2 | 37534859200 |
| 3 | -30328412970240000 |
| 4 | -482606811957501440000 |
| 5 | -2983637890141033828147200000 |