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 | 12 |
| 5 | 24 |
| 6 | 120 |
| 7 | 144 |
| 8 | 288 |
| 9 | 720 |
| 10 | 2880 |
| 11 | 5040 |
| 12 | 17280 |
| 13 | 34560 |
| 14 | 40320 |
| 15 | 86400 |
| 16 | 362880 |
| 17 | 2073600 |
| 18 | 3628800 |
| 19 | 12441600 |
| 20 | 24883200 |
| 21 | 39916800 |
| 22 | 203212800 |
| 23 | 435456000 |
| 24 | 479001600 |
| 25 | 6227020800 |
| 26 | 10450944000 |
| 27 | 14631321600 |
| 28 | 62705664000 |
| 29 | 87178291200 |