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 | 4 |
| 1 | 80 |
| 2 | 896 |
| 3 | 7680 |
| 4 | 56320 |
| 5 | 372736 |
| 6 | 2293760 |
| 7 | 13369344 |
| 8 | 74711040 |
| 9 | 403701760 |
| 10 | 2122317824 |
| 11 | 10905190400 |
| 12 | 54962159616 |
| 13 | 272461987840 |
| 14 | 1331439861760 |
| 15 | 6425271074816 |
| 16 | 30666066493440 |
| 17 | 144929376436224 |
| 18 | 678948430151680 |