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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 24 |
| 5 | 240 |
| 6 | 2160 |
| 7 | 30240 |
| 8 | 524160 |
| 9 | 9434880 |
| 10 | 188697600 |
| 11 | 4311014400 |
| 12 | 108254361600 |
| 13 | 2939153817600 |
| 14 | 86568043161600 |
| 15 | 2753962219008000 |
| 16 | 93838712647680000 |
| 17 | 3409619685728256000 |
| 18 | 131735241369059328000 |