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 | 20 |
| 2 | 62 |
| 3 | -12280 |
| 4 | -308468 |
| 5 | 10433200 |
| 6 | 729974920 |
| 7 | -6559031200 |
| 8 | -1858301284720 |
| 9 | -19430405329600 |
| 10 | 5264344401526240 |
| 11 | 170961658044572800 |
| 12 | -16153599323983104320 |
| 13 | -1016492471508449363200 |
| 14 | 50649065999412773118080 |
| 15 | 5823023695166237849024000 |
| 16 | -140330290713698002728185600 |