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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 24 |
| 6 | 5 |
| 7 | 720 |
| 8 | 105 |
| 9 | 2240 |
| 10 | 189 |
| 11 | 3628800 |
| 12 | 385 |
| 13 | 479001600 |
| 14 | 19305 |
| 15 | 896896 |
| 16 | 2027025 |
| 17 | 20922789888000 |
| 18 | 85085 |
| 19 | 6402373705728000 |
| 20 | 8729721 |
| 21 | 47297536000 |
| 22 | 1249937325 |
| 23 | 1124000727777607680000 |
| 24 | 37182145 |
| 25 | 41363226782215962624 |
| 26 | 608142583125 |
| 27 | 1524503639859200000 |