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 | -60 |
| 2 | 8460 |
| 3 | -1459680 |
| 4 | 273388620 |
| 5 | -53595097560 |
| 6 | 10818138134880 |
| 7 | -2228446076600640 |
| 8 | 465957083177325900 |
| 9 | -98553257565313635420 |
| 10 | 21034800052217022675960 |
| 11 | -4522762142866403196901920 |
| 12 | 978397734079422399475947360 |