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 | -3 |
| 1 | 12 |
| 2 | 60 |
| 3 | -420 |
| 4 | 4620 |
| 5 | 60060 |
| 6 | 1021020 |
| 7 | -19399380 |
| 8 | 446185740 |
| 9 | 12939386460 |
| 10 | -401120980260 |
| 11 | -14841476269620 |
| 12 | -608500527054420 |
| 13 | 26165522663340060 |
| 14 | -1229779565176982820 |
| 15 | -65178316954380089460 |
| 16 | 3845520700308425278140 |
| 17 | 234576762718813941966540 |
| 18 | -15716643102160534111758180 |