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 | 2 |
| 2 | 6 |
| 3 | 90 |
| 4 | 210 |
| 5 | 2100 |
| 6 | 4620 |
| 7 | 140140 |
| 8 | 300300 |
| 9 | 5105100 |
| 10 | 96996900 |
| 11 | 4481256780 |
| 12 | 9369900540 |
| 13 | 243617414040 |
| 14 | 18739801080 |
| 15 | 1164544781400 |
| 16 | 2406725881560 |
| 17 | 2700346439110320 |
| 18 | 5559536786403600 |
| 19 | 7816708721683461600 |