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 | 52 |
| 3 | 600 |
| 4 | 8680 |
| 5 | 151200 |
| 6 | 3082240 |
| 7 | 71998080 |
| 8 | 1896294400 |
| 9 | 55601145600 |
| 10 | 1796277683200 |
| 11 | 63397990656000 |
| 12 | 2427084884224000 |
| 13 | 100175046107136000 |
| 14 | 4434284662872064000 |
| 15 | 209554432423784448000 |
| 16 | 10530302071553904640000 |
| 17 | 560682451860226375680000 |