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 | 4 |
| 3 | 36 |
| 4 | 576 |
| 5 | 14400 |
| 6 | 518400 |
| 7 | 25401600 |
| 8 | 1625702400 |
| 9 | 131681894400 |
| 10 | 13168189440000 |
| 11 | 1593350922240000 |
| 12 | 229442532802560000 |
| 13 | 38775788043632640000 |
| 14 | 7600054456551997440000 |
| 15 | 1710012252724199424000000 |
| 16 | 437763136697395052544000000 |
| 17 | 126513546505547170185216000000 |