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 | 36 |
| 2 | 900 |
| 3 | 19800 |
| 4 | 415800 |
| 5 | 8648640 |
| 6 | 181621440 |
| 7 | 3891888000 |
| 8 | 85621536000 |
| 9 | 1940754816000 |
| 10 | 45413662694400 |
| 11 | 1098184934246400 |
| 12 | 27454623356160000 |
| 13 | 709596419051520000 |
| 14 | 18956361480376320000 |
| 15 | 523195576858386432000 |