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 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 93 |
| 5 | 804 |
| 6 | 8487 |
| 7 | 105720 |
| 8 | 1520313 |
| 9 | 24790800 |
| 10 | 451823403 |
| 11 | 9101380320 |
| 12 | 200808312405 |
| 13 | 4816068148800 |
| 14 | 124749498365775 |
| 15 | 3470782979053440 |
| 16 | 103225781141381745 |
| 17 | 3268196553960218880 |
| 18 | 109745731806193831635 |
| 19 | 3895876984699452280320 |