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 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 630 |
| 8 | 28560 |
| 9 | 1330560 |
| 10 | 74314800 |
| 11 | 5057098200 |
| 12 | 413836259760 |
| 13 | 40145915529720 |
| 14 | 4558576721418720 |
| 15 | 599227672837944150 |
| 16 | 90306248160926397600 |
| 17 | 15470047011889029399840 |
| 18 | 2989635481745274974582880 |