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 | 6 |
| 1 | 84 |
| 2 | 1200 |
| 3 | 17325 |
| 4 | 252252 |
| 5 | 3699696 |
| 6 | 54609984 |
| 7 | 810616950 |
| 8 | 12092280200 |
| 9 | 181176906768 |
| 10 | 2725140250560 |
| 11 | 41132585656890 |
| 12 | 622787147955000 |
| 13 | 9456196695480000 |
| 14 | 143946539451475200 |
| 15 | 2196309308974461450 |
| 16 | 33581927605139911800 |
| 17 | 514470608092210770000 |
| 18 | 7895695609776494520000 |