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 | 3 |
| 2 | 36 |
| 3 | 108 |
| 4 | 6480 |
| 5 | 3888 |
| 6 | 326592 |
| 7 | 139968 |
| 8 | 8398080 |
| 9 | 5038848 |
| 10 | 665127936 |
| 11 | 181398528 |
| 12 | 990435962880 |
| 13 | 6530347008 |
| 14 | 78364164096 |
| 15 | 235092492288 |
| 16 | 239794342133760 |
| 17 | 8463329722368 |
| 18 | 13507474236899328 |
| 19 | 304679870005248 |
| 20 | 201088714203463680 |