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 | 6 |
| 2 | 120 |
| 3 | 1680 |
| 4 | 362880 |
| 5 | 7983360 |
| 6 | 6227020800 |
| 7 | 186810624000 |
| 8 | 355687428096000 |
| 9 | 121645100408832000 |
| 10 | 51090942171709440000 |
| 11 | 213653030899875840000 |
| 12 | 1723467782592331776000000 |
| 13 | 64431180179990249472000000 |