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 | -5 |
| 2 | -10 |
| 3 | 330 |
| 4 | 2760 |
| 5 | -82680 |
| 6 | -1593360 |
| 7 | 40988880 |
| 8 | 1552095360 |
| 9 | -31261956480 |
| 10 | -2267818248960 |
| 11 | 29423279911680 |
| 12 | 4603691259048960 |
| 13 | -17797429029473280 |
| 14 | -12287671292043970560 |
| 15 | -95184807512707307520 |