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 | 20 |
| 3 | 810 |
| 4 | 28080 |
| 5 | 596700 |
| 6 | 5012280 |
| 7 | 29238300 |
| 8 | 1938081600 |
| 9 | 7994586600 |
| 10 | 328666338000 |
| 11 | 14822851843800 |
| 12 | 48511151488800 |
| 13 | 367876232123400 |
| 14 | 20997243402735600 |
| 15 | 427443883555689000 |
| 16 | 55624697380046995200 |
| 17 | 59101240966299932400 |
| 18 | 479763014902905333600 |