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 | 3 |
| 3 | 24 |
| 4 | 400 |
| 5 | 11700 |
| 6 | 536256 |
| 7 | 35631232 |
| 8 | 3245577984 |
| 9 | 388702800000 |
| 10 | 59265098200000 |
| 11 | 11212953038217216 |
| 12 | 2578459154484215808 |
| 13 | 708372581870426497024 |
| 14 | 229171184991141120000000 |
| 15 | 86242576440372042240000000 |
| 16 | 37355382389967084527220883456 |
| 17 | 18452600861204793901808906698752 |