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 | 3 |
| 2 | 16 |
| 3 | 132 |
| 4 | 2016 |
| 5 | 44928 |
| 6 | 1551744 |
| 7 | 68542848 |
| 8 | 4211122176 |
| 9 | 309852407808 |
| 10 | 29839376553984 |
| 11 | 3304540891072512 |
| 12 | 460231661327007744 |
| 13 | 71669823905083834368 |
| 14 | 13644939814369185890304 |
| 15 | 2845529932444144841981952 |
| 16 | 710399582113730769218174976 |
| 17 | 191237460565395319832268767232 |