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 | 4 |
| 2 | -226 |
| 3 | -2840 |
| 4 | 152716 |
| 5 | 3359984 |
| 6 | -171346424 |
| 7 | -5564082464 |
| 8 | 268004512400 |
| 9 | 11844081699904 |
| 10 | -536337501207584 |
| 11 | -30808027718598016 |
| 12 | 1304498317340196544 |
| 13 | 94684505764169424640 |
| 14 | -3725213683295580628864 |
| 15 | -335691960262188333195776 |
| 16 | 12179757829314204349993216 |