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 | -1058 |
| 3 | -79480 |
| 4 | 3038092 |
| 5 | 524289200 |
| 6 | -11661906680 |
| 7 | -4819720055200 |
| 8 | 22627018472080 |
| 9 | 56669755093294400 |
| 10 | 836483365475254240 |
| 11 | -809515361950727267200 |
| 12 | -29605827454506672845120 |
| 13 | 13571164223599790810028800 |
| 14 | 832572138044715293306980480 |