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 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 12 |
| 6 | 72 |
| 7 | 504 |
| 8 | 4032 |
| 9 | 36288 |
| 10 | 36288 |
| 11 | 399168 |
| 12 | 4790016 |
| 13 | 62270208 |
| 14 | 871782912 |
| 15 | 1307674368 |
| 16 | 20922789888 |
| 17 | 355687428096 |
| 18 | 6402373705728 |
| 19 | 121645100408832 |
| 20 | 243290200817664 |
| 21 | 5109094217170944 |
| 22 | 112400072777760768 |
| 23 | 2585201673888497664 |
| 24 | 62044840173323943936 |