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 | -20 |
| 3 | 188 |
| 4 | 5260 |
| 5 | -6244 |
| 6 | -2601620 |
| 7 | -32352772 |
| 8 | 1819651660 |
| 9 | 70205109596 |
| 10 | -1222831819220 |
| 11 | -150917074955332 |
| 12 | -1035896603485940 |
| 13 | 350980640716235036 |
| 14 | 12868008338514067180 |
| 15 | -796662150577236175492 |