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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 362880 |
| 10 | 362880 |
| 11 | 362880 |
| 12 | 725760 |
| 13 | 2177280 |
| 14 | 8709120 |
| 15 | 43545600 |
| 16 | 261273600 |
| 17 | 1828915200 |
| 18 | 14631321600 |
| 19 | 131681894400 |
| 20 | 263363788800 |
| 21 | 526727577600 |
| 22 | 2106910310400 |
| 23 | 12641461862400 |
| 24 | 101131694899200 |