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 | -4 |
| 2 | -48 |
| 3 | 2304 |
| 4 | 552960 |
| 5 | -796262400 |
| 6 | -8026324992000 |
| 7 | 647242847354880000 |
| 8 | 469742968896277708800000 |
| 9 | -3409206571061625099386880000000 |
| 10 | -272169233711505353534412423168000000000 |