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 | 0 |
| 1 | 2 |
| 2 | 160 |
| 3 | 21060 |
| 4 | 4352000 |
| 5 | 1313845000 |
| 6 | 547573478400 |
| 7 | 301758856490000 |
| 8 | 212663770808320000 |
| 9 | 186659516597629140000 |
| 10 | 199722414913149440000000 |
| 11 | 255947740845844788169000000 |
| 12 | 387074162712817024892928000000 |
| 13 | 682170272459193898736228210000000 |