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 | 20 |
| 3 | 1680 |
| 4 | 51240 |
| 5 | 1173512 |
| 6 | 31006978 |
| 7 | 788946320 |
| 8 | 18721725280 |
| 9 | 435630242080 |
| 10 | 9998202729808 |
| 11 | 225310437716462 |