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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 96 |
| 5 | 3528 |
| 6 | 199620 |
| 7 | 15908400 |
| 8 | 1697149440 |
| 9 | 233631921600 |
| 10 | 40335000693120 |
| 11 | 8536048230528000 |
| 12 | 2173422135804796800 |
| 13 | 655519296840629760000 |
| 14 | 231135191421131129932800 |
| 15 | 94208725354330431747302400 |
| 16 | 43956400457238853734678528000 |
| 17 | 23278422600113660887881093120000 |