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) |
|---|---|
| 6 | 1 |
| 7 | 6 |
| 8 | 42 |
| 9 | 280 |
| 10 | 2016 |
| 11 | 15372 |
| 12 | 125202 |
| 13 | 1086624 |
| 14 | 10032165 |
| 15 | 98284186 |
| 16 | 1019176158 |
| 17 | 11158475328 |
| 18 | 128679348616 |
| 19 | 1559469776760 |
| 20 | 19819217040840 |
| 21 | 263618581334880 |
| 22 | 3663049523187915 |
| 23 | 53081003095769880 |
| 24 | 800881711486787315 |
| 25 | 12562640594116484256 |
| 26 | 204583362011569856700 |