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) |
|---|---|
| 0 | 1 |
| 1 | 10 |
| 2 | 80 |
| 3 | 560 |
| 4 | 3584 |
| 5 | 21504 |
| 6 | 122880 |
| 7 | 675840 |
| 8 | 3604480 |
| 9 | 18743296 |
| 10 | 95420416 |
| 11 | 477102080 |
| 12 | 2348810240 |
| 13 | 11408506880 |
| 14 | 54760833024 |
| 15 | 260113956864 |
| 16 | 1224065679360 |
| 17 | 5712306503680 |
| 18 | 26456998543360 |
| 19 | 121702193299456 |