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 | -30 |
| 2 | -90 |
| 3 | -1260 |
| 4 | -24570 |
| 5 | -560196 |
| 6 | -14004900 |
| 7 | -372130200 |
| 8 | -10326613050 |
| 9 | -296029574100 |
| 10 | -8703269478540 |
| 11 | -261098084356200 |
| 12 | -7963491572864100 |
| 13 | -246255662483951400 |
| 14 | -7704284297712193800 |
| 15 | -243455383807705324080 |