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 | 6 |
| 3 | 66 |
| 4 | 1140 |
| 5 | 28280 |
| 6 | 948570 |
| 7 | 41173776 |
| 8 | 2238150600 |
| 9 | 148570107264 |
| 10 | 11804909261310 |
| 11 | 1104566746764800 |
| 12 | 120062928157552380 |
| 13 | 14986973664751315968 |
| 14 | 2127288759957421124610 |
| 15 | 340440417300990616995840 |