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 | 1 |
| 2 | 1 |
| 3 | 8 |
| 4 | 55 |
| 5 | 572 |
| 6 | 5928 |
| 7 | 113808 |
| 8 | 2536688 |
| 9 | 79981184 |
| 10 | 2501785344 |
| 11 | 102724061184 |
| 12 | 4063172935680 |
| 13 | 228978765692928 |