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) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 8 |
| 6 | 56 |
| 7 | 728 |
| 8 | 17472 |
| 9 | 768768 |
| 10 | 62270208 |
| 11 | 9278260992 |
| 12 | 2542243511808 |
| 13 | 1281290729951232 |
| 14 | 1187756506664792064 |
| 15 | 2025124843863470469120 |
| 16 | 6350791510355843391160320 |
| 17 | 36631365431732504680212725760 |
| 18 | 388622155865250142152376807587840 |