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 | 1 |
| 2 | 11 |
| 3 | 330 |
| 4 | 19140 |
| 5 | 1818300 |
| 6 | 256380300 |
| 7 | 50250538800 |
| 8 | 13065140088000 |
| 9 | 4350691649304000 |
| 10 | 1805537034461160000 |
| 11 | 913601739437346960000 |
| 12 | 553642654099032257760000 |
| 13 | 395854497680808064298400000 |
| 14 | 329746796568113117560567200000 |
| 15 | 316556924705388592858144512000000 |
| 16 | 346946389477105897772526385152000000 |