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 | 0 |
| 2 | 1 |
| 3 | 30 |
| 4 | 1260 |
| 5 | 75600 |
| 6 | 6237000 |
| 7 | 681080400 |
| 8 | 95351256000 |
| 9 | 16672848192000 |
| 10 | 3563821301040000 |
| 11 | 914714133933600000 |
| 12 | 277707211062240960000 |
| 13 | 98459829376612704000000 |
| 14 | 40319300129722902288000000 |
| 15 | 18888041368462498071840000000 |
| 16 | 10037644841525784689606400000000 |