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 | 20 |
| 3 | 45 |
| 4 | 320 |
| 5 | 6615 |
| 6 | 382200 |
| 7 | 680890228200 |
| 8 | 8169778639360 |
| 9 | 27445575588992 |
| 10 | 56626123593600 |
| 11 | 1235050901504640 |