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 | 0 |
| 2 | -2 |
| 3 | -3 |
| 4 | 4 |
| 5 | 15 |
| 6 | -62 |
| 7 | -273 |
| 8 | 1384 |
| 9 | 7935 |
| 10 | -50522 |
| 11 | -353793 |
| 12 | 2702764 |
| 13 | 22368255 |
| 14 | -199360982 |
| 15 | -1903757313 |
| 16 | 19391512144 |
| 17 | 209865342975 |
| 18 | -2404879675442 |
| 19 | -29088885112833 |
| 20 | 370371188237524 |
| 21 | 4951498053124095 |
| 22 | -69348874393137902 |
| 23 | -1015423886506852353 |
| 24 | 15514534163557086904 |
| 25 | 246921480190207983615 |
| 26 | -4087072509293123892362 |