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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 362880 |
| 10 | 3628800 |
| 11 | 39916799 |
| 12 | 479001577 |
| 13 | 6227020358 |
| 14 | 87178283010 |
| 15 | 1307674215120 |
| 16 | 20922786961440 |
| 17 | 355687370176320 |
| 18 | 6402372516146880 |
| 19 | 121645075013280000 |
| 20 | 2432901444395385600 |
| 21 | 51090929159028595200 |
| 22 | 1124000415686590747031 |