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 | 12 |
| 3 | 540 |
| 4 | 39744 |
| 5 | 3598992 |
| 6 | 363776832 |
| 7 | 39348690624 |
| 8 | 4456429954560 |
| 9 | 521760612125952 |
| 10 | 62642882007530496 |
| 11 | 7670452375558388736 |
| 12 | 954216689151845302272 |
| 13 | 120261048050627578368000 |