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 | 66 |
| 3 | 110 |
| 4 | -6528 |
| 5 | -21780 |
| 6 | 986898 |
| 7 | 5029200 |
| 8 | -173972160 |
| 9 | -1211972300 |
| 10 | 33051614904 |
| 11 | 297628438800 |
| 12 | -6538730283946 |
| 13 | -73793338948560 |
| 14 | 1321581552446628 |
| 15 | 18387553507364580 |
| 16 | -269415270699505128 |
| 17 | -4592418987961074600 |
| 18 | 54819166320379762180 |
| 19 | 1147693439998612940400 |