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 | 1 |
| 2 | 6 |
| 3 | 54 |
| 4 | 680 |
| 5 | 11160 |
| 6 | 226800 |
| 7 | 5504688 |
| 8 | 155433600 |
| 9 | 5006655360 |
| 10 | 181193760000 |
| 11 | 7279267564800 |
| 12 | 321452513141760 |
| 13 | 15477343917235200 |
| 14 | 806956698772224000 |
| 15 | 45293698702796544000 |
| 16 | 2723112069367173120000 |
| 17 | 174590385277914250444800 |