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 | 20 |
| 2 | -178 |
| 3 | -26680 |
| 4 | -224948 |
| 5 | 57185200 |
| 6 | 1793803720 |
| 7 | -162442199200 |
| 8 | -10506573835120 |
| 9 | 541001252398400 |
| 10 | 65475222138262240 |
| 11 | -1817482796097507200 |
| 12 | -452641118277021465920 |
| 13 | 3553238308191880620800 |
| 14 | 3472210128897376907338880 |
| 15 | 40691398188058840163264000 |