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 | 210 |
| 2 | -1260 |
| 3 | 232680 |
| 4 | -28907970 |
| 5 | 4211355960 |
| 6 | -671557897080 |
| 7 | 113817372354240 |
| 8 | -20151698294479500 |
| 9 | 3687092782592216970 |
| 10 | -692109989731133096760 |
| 11 | 132609267059636375116920 |
| 12 | -25838624519733523814390760 |
| 13 | 5105657091664960508653858680 |