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 | 24 |
| 4 | 120 |
| 5 | 720 |
| 6 | 5040 |
| 7 | 40318 |
| 8 | 362804 |
| 9 | 3626872 |
| 10 | 39874764 |
| 11 | 478139586 |
| 12 | 6209677488 |
| 13 | 86828161058 |
| 14 | 1300490408860 |
| 15 | 20771844841954 |
| 16 | 352424863147204 |
| 17 | 6329638315606052 |
| 18 | 119970031702245396 |
| 19 | 2393022889885984816 |