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 | -23 |
| 2 | 575 |
| 3 | -15525 |
| 4 | 449673 |
| 5 | -13887975 |
| 6 | 454991175 |
| 7 | -15742117125 |
| 8 | 573015200625 |
| 9 | -21871632491415 |
| 10 | 872889859083375 |
| 11 | -36333045693685125 |
| 12 | 1573742270610365625 |
| 13 | -70792055252958414375 |
| 14 | 3301204645547137704375 |
| 15 | -159327445416522130873125 |