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 | 6 |
| 2 | 1 |
| 3 | 720 |
| 4 | 120 |
| 5 | 1 |
| 6 | 362880 |
| 7 | 60480 |
| 8 | 504 |
| 9 | 1 |
| 10 | 479001600 |
| 11 | 79833600 |
| 12 | 665280 |
| 13 | 1320 |
| 14 | 1 |
| 15 | 1307674368000 |
| 16 | 217945728000 |
| 17 | 1816214400 |
| 18 | 3603600 |
| 19 | 2730 |
| 20 | 1 |
| 21 | 6402373705728000 |
| 22 | 1067062284288000 |
| 23 | 8892185702400 |
| 24 | 17643225600 |
| 25 | 13366080 |
| 26 | 4896 |
| 27 | 1 |