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 | 2 |
| 2 | 12 |
| 3 | 24 |
| 4 | 720 |
| 5 | 1440 |
| 6 | 60480 |
| 7 | 120960 |
| 8 | 3628800 |
| 9 | 7257600 |
| 10 | 479001600 |
| 11 | 958003200 |
| 12 | 2615348736000 |
| 13 | 5230697472000 |
| 14 | 31384184832000 |
| 15 | 62768369664000 |
| 16 | 32011868528640000 |
| 17 | 64023737057280000 |
| 18 | 51090942171709440000 |
| 19 | 102181884343418880000 |
| 20 | 33720021833328230400000 |
| 21 | 67440043666656460800000 |