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 | -2520 |
| 2 | 2457000 |
| 3 | -1113204960 |
| 4 | 199879986600 |
| 5 | 4992350445936 |
| 6 | -3054519828108000 |
| 7 | -316433406335739840 |
| 8 | -15444821445342229080 |
| 9 | -469944493113793897080 |
| 10 | -9973874479528786860432 |
| 11 | -158211337782226162119840 |
| 12 | -1972932224893221543809760 |