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 | 192 |
| 3 | 5952 |
| 4 | 137664 |
| 5 | 2907456 |
| 6 | 59398080 |
| 7 | 1197999936 |
| 8 | 24040445376 |
| 9 | 481452900672 |
| 10 | 9634211218368 |
| 11 | 192725453785920 |
| 12 | 3854838922404288 |
| 13 | 77099417255585088 |
| 14 | 1542009455673733056 |
| 15 | 30840357998277021504 |
| 16 | 616808511044877643200 |
| 17 | 12336181029535005559104 |
| 18 | 246723707059807997713344 |