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 | 40320 |
| 8 | 362878 |
| 9 | 3628706 |
| 10 | 39913932 |
| 11 | 478928016 |
| 12 | 6225275778 |
| 13 | 87138262602 |
| 14 | 1306763837486 |
| 15 | 20901947961712 |
| 16 | 355203011199460 |
| 17 | 6390875986594862 |
| 18 | 121365402664456728 |
| 19 | 2425912530967520904 |