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 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 38 |
| 6 | 720 |
| 7 | 26614 |
| 8 | 1858122 |
| 9 | 250586792 |
| 10 | 66121926720 |
| 11 | 34442540326456 |
| 12 | 35611003057733928 |
| 13 | 73321307277341501168 |
| 14 | 301201690357187097528960 |
| 15 | 2471354321681605983102370864 |
| 16 | 40525241311304939167532163726672 |