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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | -4 |
| 5 | -24 |
| 6 | -42 |
| 7 | 104 |
| 8 | 888 |
| 9 | 1792 |
| 10 | -8086 |
| 11 | -68608 |
| 12 | -115468 |
| 13 | 1203840 |
| 14 | 8863806 |
| 15 | 5570816 |
| 16 | -275344656 |
| 17 | -1636425728 |
| 18 | 2488177106 |
| 19 | 86205304832 |
| 20 | 369676840940 |
| 21 | -2289265803264 |
| 22 | -34139482063962 |
| 23 | -73881736609792 |
| 24 | 1691837365047912 |