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 | 6 |
| 2 | 30 |
| 3 | 120 |
| 4 | 720 |
| 5 | 2010 |
| 6 | 23820 |
| 7 | 46950 |
| 8 | 434700 |
| 9 | 1683450 |
| 10 | 15126810 |
| 11 | 36284466 |
| 12 | 547180200 |
| 13 | 1088416050 |
| 14 | 13060942950 |
| 15 | 58782162480 |
| 16 | 352913410080 |
| 17 | 1057916846190 |
| 18 | 16926687985950 |
| 19 | 33853322280030 |